Windows 11 Insider Build 26220 Deduplicates File Explorer Indexing for Faster Searches

Microsoft says a small but practical change to File Explorer’s search pipeline in Windows 11 Insider Preview Build 26220.7523 should reduce redundant work in the indexer, leading to faster searches and lower transient RAM use when hunting for files across multiple folders and drives.

Background​

Microsoft has been iterating on Windows Search and File Explorer across multiple Insider builds during the past year, experimenting with both performance tweaks and AI-driven search features. The December preview notes for the 26220.x stream list a terse but important improvement: the File Explorer search path will avoid duplicate file indexing operations. Microsoft frames this as a reliability and performance fix that is being gradually rolled out to Insiders who opt into certain toggles, not as an immediate change for all users.
This is part of a broader set of File Explorer experiments that have included preloading Explorer in the background to reduce launch latency and early trials of semantic (AI) search on Copilot+ devices. Those changes have produced mixed feedback: some preloading experiments improved perceived launch times but increased background memory use, while the indexer deduplication aims specifically to cut unnecessary resource consumption during search and indexing activity.

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What Microsoft changed in Build 26220.7523​

• The release notes for Windows 11 Insider Preview Build 26220.7523 list an update under File Explorer: “Made some improvements to File Explorer search performance by eliminating duplicate file indexing operations, which should result in faster searches and reduced system resource usage during file operations.”
• The change is being deployed as a controlled experiment — available to Insiders who have chosen the “get the latest updates” toggle — and is not yet flipped on by default for all channels.
• The update is targeted at the Windows Search Indexer pipeline that File Explorer uses; it’s not a separate search engine inside Explorer, but an optimization to the existing indexing and query path used system-wide.

These are incremental, low-profile adjustments rather than a full re-architecture of search. The aim is to reduce redundant work the indexer performs (and the transient memory, CPU, and I/O pressure that accompanies it) when the system would otherwise re-scan or re-index the same file objects through multiple paths or indexing operations.

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Why duplicate indexing matters​

The problem in plain terms​

File search and indexing are not just simple name lookups; they involve scanning file metadata and content (when enabled), maintaining index structures, and keeping those structures up to date as storage changes. When the indexer performs the same work more than once — for example, encountering identical file paths, reprocessing symlinked or mirrored entries, or redundantly indexing files across multiple locations — it wastes CPU time, produces extra disk activity, and temporarily inflates memory usage.
On systems with many files, multiple drives, or cloud-sync placeholders (OneDrive, provider storage), that redundancy can be measurable: users notice spikes in memory or CPU when performing wide searches or when background indexing runs.

What deduplication likely does​

The release note uses the phrase “eliminating duplicate file indexing operations.” That strongly suggests the indexer now performs some form of detection or canonicalization to avoid re-indexing the exact same file object multiple times. Practically speaking, this can reduce transient RAM pressure during indexing and when File Explorer executes wide queries, because fewer indexing tasks run in parallel and the indexer has fewer duplicate entries to manage in memory.
It is important to note the implementation details — e.g., whether deduping is done by path canonicalization, file ID, hash, or cache deduplication — are not described in the short release note. Those specifics remain an implementation detail inside Microsoft’s indexer and are not publicly documented in the preview notes.

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How this fits with other File Explorer experiments​

Microsoft has been testing multiple, concurrent File Explorer improvements in Insider builds:

• Preloading File Explorer in the background to reduce launch latency. This can make Explorer appear faster to open but increases baseline RAM use because parts of Explorer stay resident in memory.
• AI/semantic search on Copilot+ PCs, which introduces semantic indexing and local NPU-accelerated models that index document and image content differently. That effort focuses on richer search capabilities rather than raw memory optimization.
• Context-menu and UI experiments, including new AI actions and redesigned menus, which affect perceived responsiveness but not necessarily indexer memory usage.

The deduplication change is deliberately narrow: it addresses inefficiency in the indexing pipeline rather than changing how results are presented or introducing a separate semantic engine. That focus means it’s complementary to AI search work and to UI experiments; however, net system memory behavior will depend on which experiments are enabled on a device. For example, preloading Explorer can increase baseline RAM usage while deduplicating indexing reduces transient search-related memory spikes.

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What users (and admins) should expect​

• Modest, targeted improvement: The change aims to reduce redundant indexer work and should result in faster search queries and lower transient resource usage while indexing or running file searches. Expect incremental rather than dramatic differences on most systems.
• Gradual rollout: The feature is being deployed as an experiment for Windows Insiders who have enabled the “get the latest updates” toggle. It will be further validated with telemetry and Feedback Hub input before broader release.
• Not a complete cure for Explorer memory complaints: File Explorer’s RAM footprint and responsiveness are influenced by a range of factors — UI framework choices, preloading settings, extensions, shell extensions, cloud providers, and other concurrent experiments. This indexing change addresses one specific source of inefficiency.
• Behavior may vary by setup: Systems with many mirrored or duplicated file paths (for example, heavy use of libraries, junctions, or cloud placeholders) may see a larger benefit. Conversely, systems with simple folder layouts may see little measurable change.

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Practical testing and validation (how to measure the impact)​

For power users, IT pros, and testers who want to evaluate whether deduplication helps on their machines, here are practical steps and tools to validate the impact:

• Confirm build and experiment status:
• Open Win + R → type winver to confirm you’re on Build 26220.x (or newer).
• Ensure you are enrolled in Windows Insider Program (Settings > Windows Update > Windows Insider Program) and toggled to receive the latest experimental updates if you want the staged changes.
• Reproduce a baseline:
• Use a representative workload — e.g., a large folder tree with many files or a workspace synchronized with OneDrive — and run a wide search from File Explorer (searching by extension or broad terms).
• Record baseline metrics using Task Manager or Resource Monitor for memory, CPU, and disk I/O during indexing or search.
• Use advanced tracing for precise results:
• For deep measurement, use Windows Performance Recorder (WPR) to capture search/indexer activity and analyze with Windows Performance Analyzer (WPA). Capture traces during indexing and wide searches before and after the change.
• Look at memory allocations attributed to SearchIndexer.exe or SearchHost.exe processes; also monitor disk I/O patterns and CPU threads created by indexer tasks.
• Compare results:
• Note differences in peak memory, average CPU during indexing/search, duration to return results, and disk IOPS.
• Share reproducible traces and observations through the Feedback Hub (WIN + F) under Files Folders and Online Storage > File Explorer Search.

These steps help separate perceived responsiveness from real resource consumption and provide concrete telemetry that Microsoft often uses when validating experiments.

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Benefits and strengths​

• Focused optimization: Targeting duplicate indexing is an efficient way to cut wasted work; removing redundancy is a low-risk, high-return engineering pattern.
• Potentially lower transient RAM use: By avoiding parallel duplicate index operations, the change can reduce memory pressure spikes during large searches or when indexing multiple paths.
• Faster search results in many scenarios: Systems with many mirrored or duplicated file paths should see reduced latencies for wide queries because the indexer performs fewer redundant passes.
• Telemetry-driven rollout: Microsoft’s staged experiment approach lets the company measure real-world impact and rollback or adjust behavior before flipping defaults widely.

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Risks, limitations, and unresolved questions​

• Implementation details are undisclosed: The release note does not specify how duplicate operations are detected or canonicalized. That leaves open edge-case behavior questions, such as how network shares, symlinks, junctions, or provider placeholders are treated.
• Possible incompatibility with some storage scenarios: Systems using unconventional filesystems, third-party storage providers, or complex mount setups could surface edge cases where de-duplication introduces missed updates or stale index entries if canonicalization is imperfect.
• Interaction with other experiments: Because Microsoft is concurrently testing Explorer preloading and semantic search, total memory use and perceived performance will depend on which experiments are active. Users may see mixed results if multiple experiments interact in unexpected ways.
• Limited immediate effect for many users: On devices without duplicate indexing patterns, the benefit will be small to non-existent. Also, the feature is experimental and gated, so wide user impact will only appear after broader rollout — if Microsoft chooses to enable it by default.
• No instant fix for long-standing Explorer criticisms: Observations from community tests show File Explorer may still feel sluggish in navigation or context menus, and some UI-driven memory increases (from preloading or WinUI elements) are separate concerns that this fix does not address.

Given those caveats, Microsoft and testers will need to watch for bug reports that highlight indexing edge cases and for telemetry that confirms reduced resource usage at scale.

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How to enable, test, and give feedback (Insider instructions)​

• Join the Windows Insider Program if you’re not already enrolled: Settings > Windows Update > Windows Insider Program. Choose the Dev or Beta channel as applicable.
• Ensure you have the latest preview build installed and that the Insider toggle is enabled for receiving the newest staged updates.
• Verify your build via Winver; the new indexing behavior appears in the 26220.x build family (Build 26220.7523 is the preview that first listed the change).
• To examine or adjust what’s indexed on your machine: Settings > Privacy & security > Searching Windows. Use the “Enhanced” indexing option to index the whole PC or specify custom locations if you want targeted indexing.
• File feedback in Feedback Hub (WIN + F) under Files Folders and Online Storage > File Explorer Search with reproducible steps and performance traces if possible.

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Enterprise considerations and admin guidance​

For IT administrators managing fleets, the change is notable but not disruptive by itself. Because it’s an indexer optimization:

• Expect no changes to core file access semantics or permissions; this is an indexer-side optimization, not a change to file ACLs or storage APIs.
• Test on pilot groups before broad deployment. Validate search reliability across network shares, DFS namespaces, and cloud-enabled folders used in the organization.
• If you run managed devices that do not participate in the Insider program, you will not see this experimental change until it rolls into production channels.
• Keep an eye on telemetry for search-related errors and index corruption reports; if unusual behaviors appear after the change, gather Feedback Hub reports and WPR traces.

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What this means for the broader Windows 11 performance conversation​

The deduplication update demonstrates a practical, incremental approach to performance — addressing a specific, measurable inefficiency in the indexing pipeline rather than attempting sweeping UI or architectural changes. That engineering approach has advantages: it reduces risk, is easier to validate, and typically delivers predictable improvements.
However, it also highlights a broader truth: perceived sluggishness and inflated memory use in Windows 11 come from multiple sources. UI choices (WinUI/XAML elements), optional preloading experiments, third‑party shell extensions, complex cloud sync behavior, and powerful but memory-hungry AI features all affect the overall experience. This difference in scope helps explain why the community continues to see mixed results: some changes decrease resource usage in one area while others increase it in another.

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Bottom line​

Microsoft’s indexer deduplication in Windows 11 Insider Preview Build 26220.7523 is a pragmatic, low-risk optimization that should reduce redundant indexing work and trim transient RAM and CPU pressure during searches and indexing. For many users — particularly those with complex folder setups, mirrored paths, or heavy cloud sync activity — the change may produce noticeably faster searches and lower spikes in resource consumption.
That said, it’s not a silver bullet. Implementation details remain private, the change is experimental and gated, and other concurrent File Explorer experiments can offset or mask the benefits on any individual system. Users and administrators should test on representative workloads, use standard Windows performance tooling to validate impact, and file reproducible Feedback Hub reports when they find regressions or unexpected results.
Expect this kind of focused optimization to continue: Microsoft is balancing feature innovation (AI search, enhanced UI, Copilot integrations) with steady performance work, and the success of this change will depend on how it interacts with the broader set of Explorer experiments as they move from Insider rings to production releases.

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Source: Wccftech Microsoft Rolling Out An Update To Reduce RAM Usage In Windows 11 File Explorer Search Feature

 

[ChatGPT]

Microsoft’s quietly delivered File Explorer tweak in Windows 11 Insider Preview Build 26220.7523 is a deliberately small, high‑leverage optimization: the Windows Search indexer now avoids duplicate file‑indexing operations, a change Microsoft says will yield faster search results and lower system resource use during file operations.

Background​

File Explorer is more than a file browser; it’s the daily performance front door for most Windows users. On many systems, heavy searches or background indexing can trigger spikes in disk I/O, CPU cycles and transient RAM use that make the whole machine feel sluggish. Microsoft has been testing targeted fixes in the 26220 build stream to address those pain points without a full rework of Explorer’s architecture. The official release notes for Build 26220.7523 state the change concisely: “Made some improvements to File Explorer search performance by eliminating duplicate file indexing operations, which should result in faster searches and reduced system resource usage during file operations.” This indexer deduplication is being deployed as a staged experiment in the Windows Insider Dev and Beta channels via a controlled feature rollout. Insiders who opt into the earliest updates can see the behavior sooner; Microsoft is collecting telemetry and Feedback Hub input before deciding broader rollout timing. Independent reporting and community testing confirm the note is present in the 26220.* preview stream.

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What Microsoft changed — plain English​

• Previously, the Windows Search indexer sometimes enqueued or ran the same indexing work more than once — for example, when the same file was reachable through multiple logical paths, cloud placeholders reappeared, or several subsystems requested updates concurrently.
• The update introduces deduplication in the indexing pipeline: the indexer coalesces or canonicalizes identical work items so the same physical file object is not processed multiple times concurrently.
• The visible effect: fewer redundant reads and threads devoted to identical tasks, which reduces transient memory allocations and I/O spikes and can make searches return results more quickly.

This is an indexer‑side optimization — File Explorer still queries the system Windows Search index as before. The change benefits any component that relies on that index, not just Explorer’s UI.

How this differs from a rewrite​

This is surgical rather than sweeping: Microsoft is not shipping a new search engine inside Explorer. Instead, engineers patched the plumbing inside the Windows Search indexer to remove redundant operations — a low‑surface‑area approach that can be validated via telemetry and rolled back if needed.

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Technical anatomy: why duplicate indexing happens​

Understanding where the gains come from requires a quick look at real‑world filesystem complexity:

• Multiple logical paths: reparse points, junctions, symbolic links and library views can expose the same physical file through different paths. Without canonicalization, each path can be queued separately.
• Transient mounts and placeholders: external drives, flaky network shares and OneDrive placeholder behavior can cause repeated enqueue events.
• Concurrent subsystem requests: backup agents, antivirus, shell extensions and third‑party filters sometimes request indexing simultaneously, producing parallel work for the same targets.
• Racey queue coalescing: if the work queue logic doesn’t coalesce identical jobs, the indexer may spawn redundant threads that reprocess the same objects.

Deduplication addresses these by canonicalizing targets, coalescing concurrent requests, and adding defensive checks around transient volumes and cloud placeholders. Microsoft’s release note is high level and does not disclose low‑level implementation details (for example, whether dedupe is done by file ID, path canonicalization, or hashes). Those specifics remain internal. Treat implementation details as informed inference until Microsoft publishes deeper engineering notes.

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Expected benefits — where gains will be largest​

This optimization is pragmatic and workload‑dependent. Expect the largest, most perceptible improvements in the following scenarios:

• Budget laptops and machines with 4–8 GB of RAM, where transient allocations meaningfully impact foreground responsiveness.
• Systems with mechanical hard drives (HDDs) or slow NVMe devices that suffer from heavy I/O spikes.
• Environments with heavy cloud‑sync activity (OneDrive placeholders), multiple mounts, or large multi‑drive setups where repeated re‑enumeration was common.
• IT fleets that require predictable background indexing behavior during maintenance windows.

Early community tests and independent outlets report smoother search behavior and lower transient memory spikes in some workloads, but the absolute figures vary widely by hardware, storage type and the exact folder mix being indexed. Microsoft has not published a universal “X MB saved” metric, so treat specific percentage claims as anecdotal until reproducible lab data appears.

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What this change will not fix​

• It will not improve raw enumeration speed across slow network shares or NAS devices: those bottlenecks are network or remote server dependent.
• It does not directly fix slow third‑party shell extensions or preview handlers that block UI operations.
• Non‑indexed full‑PC scans (when users explicitly search unindexed locations) will still be expensive.
• Preloading experiments that intentionally keep a warmed Explorer instance in memory are separate changes and can increase baseline RAM. The indexer dedupe does not eliminate those tradeoffs.

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Measured impact — what testers are seeing (and limits of those numbers)​

Community traces and early tester reports have surfaced the following patterns:

• Reduced duplicate NTFS reads and fewer concurrent indexer threads during active indexing windows.
• Lower peak working set for SearchIndexer.exe in some workloads, translating to fewer transient RAM spikes.
• Faster time‑to‑first‑result for broad searches on heavily indexed folders.

But important caveats apply:

• Gains are highly variable — the same build can show large gains on a slow HDD laptop and negligible difference on a high‑end NVMe desktop.
• Many public numbers circulating on social platforms are anecdotal. A responsible test requires controlled, repeatable baselines, ideally with Windows Performance Recorder (WPR) traces and Windows Performance Analyzer (WPA) to inspect I/O patterns and thread counts.
• Microsoft hasn’t published telemetry dashboards quantifying typical savings across device classes; community numbers should be considered early and provisional.

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How to validate the improvement on your hardware (practical steps)​

• Confirm build and enrollment:
• Settings → Windows Update → Windows Insider Program. Ensure the device is enrolled and updated to a 26220.* build (for example, 26220.7523).
• Create a representative workload:
• Use a large photo library, nested Documents with many file types, or a folder set that includes OneDrive placeholders and external mounts.
• Baseline measurement:
• Record Task Manager snapshots for SearchIndexer.exe, SearchProtocolHost.exe and explorer.exe during a wide search.
• Use Resource Monitor or Process Explorer to capture I/O and handles.
• For detailed analysis, collect a WPR trace and analyze with WPA to review duplicate reads, queueing patterns, and memory allocations.
• Install the Insider build / receive the staged experiment and repeat the identical workload.
• Compare:
• Peak and average memory for indexer processes.
• Disk I/O patterns: look for fewer repeated reads on the same files.
• Time‑to‑first‑result and time‑to‑complete for defined queries.
• Verify correctness:
• Run verification queries designed to detect missing results (symlink paths, files in mounted volumes, or recently moved/renamed items) to ensure deduplication did not drop items.

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Rollout, opt‑in and timeline​

Microsoft has deployed the change as a controlled feature rollout to selected devices in the Insider Dev and Beta channels; it’s not yet a universal update for all users. The Insider release notes include the exact phrasing about eliminating duplicate indexing operations and annotate that fixes are being rolled out with toggles and telemetry validation. Insiders who have enabled early updates can opt into staged experiments; Microsoft uses these flights to refine behavior before any GA release. Industry coverage and community reporting suggested a broader public rollout could arrive in early 2026, but those schedules remain speculative until Microsoft publishes an explicit GA plan. Treat any published calendar in third‑party posts as provisional.

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Compatibility and risk analysis​

Strengths

• Low risk: the change modifies internal indexing logic rather than external APIs, minimizing compatibility surface.
• Broad benefit: any component that reads the Windows Search index (not just Explorer) may inherit the improvements.
• Measurable: the behavior is amenable to trace‑based validation, making regressions easier to identify and fix.

Risks and caveats

• Third‑party integrations: some shell extensions, IFilter implementations or backup/antivirus agents may rely on repeated indexing events for their own change‑detection logic. Deduplication could alter their assumptions and surface functional differences.
• Edge cases: canonicalization rules around reparse points, symlinks and cloud placeholders must be robust; otherwise, dedupe could incorrectly coalesce distinct logical entries (unlikely, but worth validating).
• Preloading tradeoffs: separate Explorer preloading experiments make the overall memory profile more complex — you can get faster perceived launch at the cost of a small, persistent RAM footprint. Admins and power users should test both features together to understand net impact.

Operational guidance

• Pilot on representative hardware sets before broad enterprise deployment.
• Validate vendor‑supplied shell extensions and backup agents under the new index timing profile.
• Use Microsoft’s Feedback Hub to report regressions with clear repros so telemetry‑driven tuning can address edge cases.

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Why this matters for AI‑ready PCs and the Copilot+ story​

Microsoft’s Copilot+ PC program defines a hardware tier tuned for local AI workloads. Copilot+ certification currently requires a capable NPU, at least 16 GB of RAM and minimum storage — conditions that shape the on‑device AI experience and performance expectations. Optimizations like indexer deduplication reduce background noise and contention for memory and I/O, which makes it easier to run heavier local AI workloads without starving the NPU/CPU subsystem. In other words, small wins in the OS plumbing can compound to improve the real‑world experience of AI features running alongside traditional workloads. That said, Copilot+ PCs target mid‑to‑high‑end hardware where 16 GB is a baseline; the indexer change is arguably most meaningful to the opposite end of the spectrum — older laptops and budget devices with constrained RAM. Both trajectories matter: Microsoft optimizes for new AI use cases while still applying surgical improvements that extend the useful life of entry‑level hardware.

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Practical recommendations for Windows users and IT admins​

• Casual users (non‑Insider): Wait for the public rollout. When it arrives, verify your workflows and update policies; don’t chase anecdotal performance numbers.
• Enthusiasts and Insiders: If you test the 26220.* stream, measure with WPR/WPA and collect reproducible traces before and after. Share precise repro steps to the Feedback Hub when you hit issues.
• IT admins and help desks:
• Pilot the build on a controlled fleet sample containing the most common device profiles (HDD, low RAM, heavy OneDrive users).
• Validate third‑party shell extensions and backup agents under the new timing profile.
• Consider a staged client rollout policy tied to measured telemetry from your fleet.
• Power users: Use Process Explorer and Resource Monitor to confirm reductions in SearchIndexer.exe memory and I/O. If you rely on third‑party filters that respond to repeated index events, coordinate with vendors to ensure compatibility.

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Critical perspective: small changes, real tradeoffs​

The deduplication work is precisely the sort of practical engineering fix Windows needs more of: targeted, measurable, and low risk. It addresses a concrete inefficiency rather than reshaping user‑facing behavior or adding new surface area. At the same time, it’s modest in scope. It won’t make modern high‑end devices feel dramatically faster, nor will it single‑handedly resolve persistent Explorer complaints rooted in WinUI/XAML performance or third‑party preview handler issues.
Two broader tensions deserve attention:

• Cumulative feature cost: Microsoft is experimenting with several Explorer changes simultaneously — dedupe, preloading, context‑menu reorg — and the net memory and performance outcome depends on which combinations are enabled. Preloading delivers perceptual gains but increases idle RAM, while deduplication reduces transient spikes; the net effect needs evaluation on each device class.
• The measurement problem: without published telemetry from Microsoft or reproducible multi‑platform lab studies, community numbers remain workload‑specific anecdotes. Responsible deployment requires local measurement.

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Conclusion​

Microsoft’s insider change to “eliminate duplicate file indexing operations” is a welcome, low‑risk efficiency improvement that should reduce transient RAM, CPU and I/O spikes during searches and indexing windows. It’s a thoughtful, telemetry‑driven fix delivered as a controlled experiment to Insiders in the 26220 build stream and is already visible in Microsoft’s release notes. The feature is not a silver bullet: gains will vary by device class, third‑party integrations may surface edge cases, and preloading experiments introduce separate tradeoffs. Still, this is precisely the sort of incremental engineering that can make Windows 11 feel snappier across a wider range of hardware — especially for users clinging to aging machines or for IT teams managing constrained fleets. Test, measure, and pilot: that is the practical path forward for anyone planning to adopt the change in production.

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Source: Notebookcheck Windows 11 File Explorer update aims to reduce RAM usage and deliver faster search performance