Windows 11 September 2025 Patch Tuesday: fixes, 25H2 ISOs, SSD saga, and debloat tools

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Microsoft pushed a busy week of changes across Windows 11 and the broader Windows ecosystem: September’s Patch Tuesday landed with a handful of quality fixes and a long-requested calendar clock return, Microsoft released ISOs for Windows 11 version 25H2 to Insiders, the SSD “bricking” saga continued with Phison blaming preview firmware, and a wave of community tooling — from Flyoobe’s hardware-bypass updates to the extreme nano11 debloat script — is reshaping how power users install and pare down Windows. (support.microsoft.com)

Background / Overview​

Windows releases, security updates, Insiders builds, third‑party tooling, and hardware/firmware interactions all collided this week. Microsoft’s September cumulative updates (Patch Tuesday) focused on security and quality fixes while adding a few small quality-of-life improvements; the Windows Insider channels continued to iterate on AI features (Copilot, Studio Effects), UI polishing (taskbar and File Explorer), and developer-facing changes; and community projects and vendor clarifications dominated the side‑stories that affect real users — especially those who tinker.
This article unpacks the technical facts, verifies major claims against multiple independent sources, flags what’s still uncertain, and highlights the practical steps Windows enthusiasts and sysadmins should take now.

September 2025 Patch Tuesday: what changed and why it matters​

Key updates and notable fixes​

Microsoft shipped September’s cumulative updates for Windows 11 and Windows 10. The Windows 11 24H2 cumulative update (LCU) is provided via KB5065426, while updates for other supported Windows 11 branches landed under KB5065431 and Windows 10 under KB5065429. These packages are security-first releases that also bundled quality improvements carried forward from prior monthly updates. (support.microsoft.com)
Important, tangible fixes in this month’s roll-up include:
  • A fix that addresses audio stuttering in applications using the Network Device Interface (NDI) when Display Capture is active in OBS — a relief for streamers and AV professionals who reported degraded NDI performance following prior updates. (support.microsoft.com)
  • A fix for unexpected UAC prompts observed for some MSI installer repair operations, which improves the reliability of app installations for non‑admin users. (support.microsoft.com)
  • Security updates across the OS and updated AI component binaries for Copilot-enabled scenarios. (support.microsoft.com)

The calendar flyout clock: small change, big cheers​

One of the most noticed user-facing tweaks was the reinstatement of a more fully featured clock inside the calendar/notification flyout — the small return of a long‑requested UI element that users missed after earlier UI changes. This hit a nerve because it’s both low-risk and high-visibility: a practical UX win that signals Microsoft is listening to iterative feedback from Insiders and production rollouts. Microsoft’s cumulative notes and Insider previews documented the calendar/notification tweaks that enable timing/seconds options in certain builds. (support.microsoft.com)

What administrators should do now​

  • Confirm application compatibility in test rings before broad deployment.
  • Prioritize firmware and driver updates for storage controllers and NVMe devices before applying large cumulative updates at scale.
  • Monitor vendor advisories for niche troubleshooting items — for example, the NDI/OBS issue was specifically addressed in this update. (support.microsoft.com)

Windows Insider program: preview builds and new feature highlights​

Canary / Dev / Beta / Release Preview churn​

Windows Insider channels continued to deliver a steady stream of features and bug fixes:
  • Canary builds rolled out new File Explorer experiments and calendar-clock toggles alongside other cosmetic and engineering changes.
  • Dev and Beta releases added Emoji 16.0 support, ongoing Copilot UX and Click-to-Do improvements, and the gradual rollout of Copilot-driven recommendations in Start.
  • Release Preview builds mirror many of these features in near‑final form and were used to seed the 25H2 ISO releases to Insiders. (blogs.windows.com)

Copilot+ PC exclusives and camera improvements​

Microsoft is expanding on-device AI features that are exclusive to Copilot+ hardware platforms (machines with on‑device NPUs). A notable addition this week is the ability to apply Windows Studio Effects to external cameras and rear-facing cameras on Copilot+ PCs — historically Studio Effects were limited to the internal front camera. This change is rolling out first to Intel-based Copilot+ devices, with AMD and Snapdragon models to follow. That means higher-tier AI camera processing (background blur, auto-framing, eye-contact correction) is now available for USB webcams on qualifying machines. (blogs.windows.com)

Ads and recommendations creep into shell surfaces​

Insider builds continue to test “recommendations” and promotional placements: Copilot suggestions may show in the Start menu’s Recommended area, and Microsoft has experimented with full‑screen prompts nudging users toward Microsoft 365 or upgrades. These experiments are source of community frustration because they blur the line between helpful recommendations and paid/promotional placements inside the OS shell. The settings to turn off such recommendations remain available, but the move is noteworthy for customers concerned about ad-like experiences inside Windows. (windowscentral.com)

Windows 11 version 25H2 ISOs: what’s available and who should (or shouldn’t) use them​

Microsoft made Windows 11 version 25H2 ISOs available to Windows Insiders via the Insider ISO page. These images allow clean installs and testing of the 25H2 release path before the broad public rollout. The Release Preview channel is acting as the distribution corridor for these ISO files ahead of the general enablement. (blogs.windows.com)
Important clarifications:
  • The 25H2 release is being delivered as an enablement package on top of 24H2 for many devices — this means most users will get a small switch to enable 25H2 rather than a monolithic re‑installation. The ISO is primarily useful for testers, IT pros building media, and those who need a clean install or offline deployment media. (tomshardware.com)
  • Insiders can use the ISO to test compatibility and collect telemetry for driver and app vendors; casual consumers should prefer Windows Update when 25H2 reaches general availability, unless they understand the risks of pre-release installs. (techradar.com)

The SSD saga: Phison, preview firmware, and why this wasn’t a straightforward Microsoft bug​

Over the last month community reports claimed that a Windows update caused SSDs to fail or “disappear” during heavy writes. That story developed into a messy public debate involving reviewers, social media clips, and high-profile YouTubers.
Two vendor and investigative threads now dominate:
  • Microsoft’s telemetry and internal investigation found no causal link between the Windows security update and a fleet‑wide pattern of physical SSD failures. Microsoft stated its findings publicly after analysis. (techradar.com)
  • Phison — the SSD controller vendor at the center of many reported incidents — concluded that most severe repro cases came from systems running engineering/preview firmware supplied for testing and media review, not consumer retail firmware. Phison’s testing regimen (thousands of testing hours) failed to reproduce the broad failure mode on production firmware, shifting the focus from the OS update to firmware provenance and distribution. (theverge.com)
What this means in practice:
  • If you are a desktop, workstation, or server admin: verify SSD firmware versions via vendor tools and apply officially published consumer firmware updates if available. Avoid using engineering/preview firmware outside of controlled lab contexts. (tomshardware.com)
  • If you are a reviewer or content creator: ensure any drives used for public tests are production firmware builds — engineering previews can behave differently under stress and can produce misleading public data that cascades into false causal claims. (theverge.com)
Caveat: while vendor test results and Microsoft’s telemetry strongly undercut the claim that Windows updates “bricked” drives en masse, a small set of environment‑specific incidents remain reported by users; these are uncommon but important for data‑sensitive customers. Keep backups and avoid sustained large-file transfers on near-capacity drives until firmware/driver states are validated.

Unsupported PCs and third‑party installers: Flyoobe’s big update and temporary GitHub hiccup​

Third‑party tooling that bypasses Windows 11 hardware checks remains popular. Flyoobe (the successor to Flyby11), a community project that streamlines Out-Of-Box Experience (OOBE) customization and hardware‑check bypasses, released a major update with stronger OOBE controls, AI-related toggles, and scriptable extensions. The project maintainer repackaged Flyby11 into Flyoobe and published new releases on GitHub. (github.com)
There was also a brief public scare when the repo was flagged by GitHub’s abuse systems and temporarily became less accessible; the project was restored and updated quickly. Reports indicate the removal was an automated flag tied to popularity and distribution patterns, not a deliberate takedown for policy violations. Still, this moment highlights the fragility of relying on third‑party tooling for system‑critical bypasses. (newsminimalist.com)
Security and stability notes for Flyoobe users:
  • Bypassing hardware checks removes platform‑level security (TPM, Secure Boot) intended to protect device integrity. That increases exposure to some classes of attacks or compatibility problems with future Windows updates.
  • Always download tooling directly from the official project page or GitHub releases, verify checksums if provided, and prefer community‑vetted forks with reproducible builds. (github.com)

Debloating extremities: nano11 and the tradeoffs of an ultra‑small Windows image​

On the debloat front, the nano11 project (an “extreme” descendant of Tiny11) demonstrated how far community scripts can go: Nano11 can build Windows 11 images that shrink installed footprints to under 3 GB on disk by removing drivers, Defender, Windows Update, language packs, and numerous system components. The technique is a combination of aggressive removal and high-compression techniques; it’s a testbed or VM tool, not a recommended daily‑driver configuration. (tomshardware.com)
Why this matters:
  • Nano11 is an engineering case study showing the modularity of modern Windows, but it does so by removing critical maintainability features (no Windows Update, limited driver support, removed security components). That’s acceptable for ephemeral VMs, embedded testbeds, or forensic images — but not for productive machines with user data. (theregister.com)
Practical guidance:
  • Use nano11 only in isolated VMs or short‑term test scenarios.
  • Never rely on a nano‑trimmed image for a device with sensitive or irreplaceable data.
  • If you need a lighter daily driver, prefer conservative tools like Tiny11 builder which preserve updateability and security serviceability. (github.com)

Microsoft’s deprecation sweep: legacy web components and VBScript​

Microsoft updated its deprecated features list, explicitly naming several EdgeHTML-era web components as deprecated: Legacy Web View, Windows 8/8.1/UWP HTML/JavaScript apps, legacy PWAs built on EdgeHTML, and Legacy Edge (EdgeHTML) DevTools. The recommended migration path is WebView2 and Chromium-based PWAs. This is part of long-term consolidation onto actively developed, Chromium-based web embedding. (windowsforum.com)
Separately, Microsoft has published a phased timeline to deprecate VBScript as a core platform feature — not immediately, but in staged phases through the remainder of the decade. Enterprises relying on VBScript in VBA projects should migrate, or at minimum, plan to enable VBScript as a Feature-on‑Demand for the interim and update Office to versions that include RegExp replacements in VBA. Microsoft provided explicit guidance on how to prepare VBA projects and alternatives for RegExp usage. (techcommunity.microsoft.com)
Impacts and recommendations:
  • Inventory: find apps that embed EdgeHTML components or call VBScript.
  • Plan: cultivate migration roadmaps to WebView2, WinUI, or supported web frameworks.
  • Mitigate: apply compatibility shims temporarily, but treat deprecation as a schedule that will eventually require code changes.

Microsoft Store, developers, and Excel/Word AI improvements​

This week also saw functional changes in the Microsoft Store policies and developer onboarding: Microsoft removed the $19 fee barrier for certain developer app submissions and clarified policies related to child safety and generative AI usage in store apps. For creators and small developers this lowers a friction point for distribution. Meanwhile, Microsoft continues to fold AI into productivity apps: Copilot is being used to assist with Excel formulas, Word Online grammar fixes, and more — aiming to speed up authoring tasks with on‑device and cloud-assisted models. (theverge.com)

Gaming, controllers, and cloud streaming notes​

Gaming‑adjacent changes this week included a change to how the Xbox button functions on controllers under Windows 11 (single press Game Bar, long press Task View, press-and-hold to power down controllers), expanded Xbox Cloud Gaming partnerships (LG cars and in‑vehicle cloud streaming), and GeForce NOW rolling out higher-tier RTX 5080-class servers — though the surge caused outages for some users. These are meaningful for handheld and cloud gaming scenarios. (windowscentral.com)

Critical analysis: strengths, risks, and where to focus attention​

Strengths​

  • Microsoft’s cadence continues to deliver incremental UX improvements (calendar clock, multi-monitor notification center behavior) while addressing real-world bugs (NDI/OBS stutters). Those quick quality fixes increase daily productivity for power users and content creators. (support.microsoft.com)
  • The availability of 25H2 ISOs to Insiders and the enablement‑package update approach minimize disruption for enterprise deployments and IT imaging workflows. (blogs.windows.com)
  • Cross‑industry validation (Microsoft + Phison + independent labs) defused a panic about mass SSD failures and redirected attention to firmware provenance, which is the right engineering path to investigate device‑level anomalies. (theverge.com)

Risks and downsides​

  • The continued appearance of promotional content (Copilot prompts, Start menu recommendations, full-screen upgrade nudges) erodes trust for some users. While toggles exist, the trend of monetization inside OS surfaces is a persistent user‑experience risk. (windowscentral.com)
  • Third‑party bypass tools like Flyoobe are pragmatic and popular, but they create a support and security burden. Installing Windows without TPM/Secure Boot or enabling unsupported hardware paths increases exposure and can result in future update blocks or functional regressions. (github.com)
  • Extreme debloat scripts such as nano11 produce impressive size reductions but do so by removing updates and security services — a deliberate tradeoff that should be limited to disposable or test environments. Using such images on primary devices is risky. (tomshardware.com)

Open questions / unverifiable areas​

  • Although Phison’s lab testing and Microsoft’s telemetry strongly indicate the Windows updates were not the root cause of the SSD reports, a small number of user‑reported incidents remain unresolved in the wild. Those edge cases deserve continued monitoring; telemetry and vendor logs are the authoritative source, but public incident reporting remains anecdotal. Treat the “bricked SSD” narrative as largely resolved but not fully closed until a final, auditable post‑mortem is published by the vendors involved. (tomshardware.com)

Practical checklist: what enthusiasts, admins, and testers should do this week​

  • Back up critical data before applying monthly cumulative updates or experimenting with new ISO installs.
  • Update SSD firmware using OEM tools and avoid applying engineering or preview firmware unless you are in a lab/test environment. (tomshardware.com)
  • If you run Copilot+ features, verify device vendor driver updates and check the Windows Studio Effects driver notes before enabling external-camera Studio Effects. (blogs.windows.com)
  • Avoid running nano11 or similar extreme debloat images on production devices; confine them to disposable VMs for testing. (tomshardware.com)
  • For organizations: inventory use of VBScript and EdgeHTML-based components now, and begin migration planning to supported technologies (WebView2, modern PWAs). (techcommunity.microsoft.com)
  • Disable Start menu recommendations and other “suggestions” toggles if you prefer a non‑promotional shell experience. (pcworld.com)

Conclusion​

This week reinforced two themes that have defined Windows in recent years: iterative, user-facing UX fixes delivered through monthly updates and Insiders channels, and a lively ecosystem of community tooling and vendor interaction that shapes how users install, optimize, or troubleshoot Windows in practice. Microsoft’s September updates patched practical issues (NDI/OBS, UAC prompts), brought back a small but meaningful calendar clock feature, and seeded 25H2 ISOs to Insiders — while the SSD story and the rise of extreme debloat tools and hardware-bypass utilities underscored the ongoing tension between official platforms and community-led customization.
For anyone managing devices or experimenting with pre-release media, the pragmatic approach remains: update firmware first, test updates in controlled rings, isolate experimental debloats to VMs, and treat third‑party bypass tools as useful but unsupported workarounds that carry real risks. The Windows ecosystem continues to mature — feature by feature and fix by fix — but the responsibility for safe deployment ultimately falls to administrators and informed users.

Source: Neowin Microsoft Weekly: new Windows 11 updates with new features, 25H2 ISOs are here, and more