Why does File Explorer keep crashing when accessing large folders on Windows 11?

Check for Problematic Shell Extensions​

• Download ShellExView (free).
• Sort by Type → Context Menu / Property Sheet / Preview / Thumbnail Handlers.
• Disable all non-Microsoft shell extensions (especially from media software, cloud sync apps, archivers).
• Reboot → test if Explorer still crashes.

1. Get ShellExView (NirSoft) and run it elevated (right‑click → Run as administrator).
   • In ShellExView: Options → Hide All Microsoft Extensions.
   • Sort by Type and focus on: Context Menu, Property Sheet, Preview, Thumbnail Handlers. Disable non‑Microsoft entries first.
2. Don’t disable everything at once. Use the binary search method:
   • Disable ~50% of third‑party handlers → test.
   • If crash persists, re-enable that half and disable the other half. Repeat until you find the single handler (or small group) that triggers the crash.
3. Test quickly without rebooting: restart Explorer instead of rebooting. In an elevated Command Prompt or PowerShell run:
   
   Code:

   taskkill /f /im explorer.exe
   start explorer.exe

   Reboot only if you prefer a full clean state.
4. Quick shortcuts to narrow the culprit
   • Disable Thumbnail/Preview handlers first (common culprits for large folders).
   • Temporarily turn off thumbnail generation: File Explorer → View → Options → View → check “Always show icons, never thumbnails” → OK. If that stops crashes, you’ve strongly narrowed it to a thumbnail/preview handler or codec.
   • If the problem occurs only in folders with many media files, suspect codecs, RAW camera plugins, media players, or cloud sync thumbnails.
5. Other tools / alternatives
   • Autoruns (Sysinternals) can also show shell extensions and context menu handlers if you prefer a different UI.
6. Logs and crash info
   • Check Event Viewer (eventvwr.msc) → Windows Logs → Application and System around the time of the crash. Look for Error entries from explorer.exe or ShellExperienceHost.exe. That often gives the offending DLL name.
   • Reliability Monitor (type “reliability” in Start) sometimes shows which module crashed.
7. Common culprits to check first
   • Cloud clients (OneDrive, Dropbox, Google Drive), compression tools (WinRAR/7‑Zip), media/codecs (K-Lite, RAW codecs), shell integration from virtualization, antivirus context menu entries, GPU drivers’ shell extensions, and photo/video editors.
8. Safety notes
   • Always use “Hide Microsoft Extensions” and avoid disabling Microsoft entries. If unsure, export a System Restore point or a simple registry backup before doing mass changes. Re-enable any disabled item if it turns out not to be the cause.
9. If you find the culprit
   • Update or uninstall the app that installed the handler, or uninstall only the shell integration if that option exists. Report the failing DLL name here if you want help interpreting it.

• The most recent Event Viewer error around the crash (copy the error text), or
• The handler/DLL name ShellExView shows for the item you suspect.

• Turned off the Preview pane / “Show preview handlers in preview pane” in Folder Options — this prevents Explorer from invoking preview handlers while selecting files.
• Used ShellExView to find and disable non‑Microsoft shell/preview/thumbnail handlers until the folder opens smoothly.

• File Explorer → View → Show → uncheck Preview pane (Alt+P toggles it). This is the quickest test to confirm a preview handler is the problem.

• Run ShellExView as admin, sort by Company, then disable non‑Microsoft Preview/Thumbnail/ContextMenu handlers (do a handful at a time). Restart Explorer and retest. If the folder opens fine, re-enable gradually to find the culprit.

• Autoruns (Sysinternals) lists more shell/COM load points; use it to disable suspect shell extensions and preview handlers. Reboot or restart Explorer to test changes.

• Disk Cleanup or Settings → Storage → Temporary files → remove Thumbnails; also File Explorer Options → General → Clear File Explorer history. Corrupt thumbnails can crash thumbnail/preview handlers.

• Recent Windows security changes block the Preview pane for files tagged as “from the Internet.” For trusted downloaded files you can restore preview by Unblocking a file (Right‑click → Properties → check Unblock) or use PowerShell’s Unblock‑File for many files — but be cautious: unblocking removes a security marker.

• Common culprits: PDF preview handlers, media codecs, image viewers, or “QuickLook”‑style apps. Update to the latest vendor build or uninstall to test. Many Explorer crashes trace back to an outdated codec/handler.

• If the issue persists, boot to a Clean Boot (disable non‑Microsoft services/startup) or Safe Mode to confirm third‑party software is the root cause.

• Reproduce the crash, then check Event Viewer → Windows Logs → Application/System for Explorer errors; that error message and faulting module name can point to the offending DLL (preview handler or shell extension).

• Disable only one or a few extensions at a time so you can roll back easily. Create a restore point before mass disabling or editing registry/policies.
• Don’t mass‑unblock files unless you trust their sources — MoTW exists to reduce a credential‑leak attack surface.

• Walk you step‑by‑step through ShellExView actions (which items to disable first).
• Help interpret an Event Viewer crash entry if you paste the faulting-module name.
• Suggest likely culprits based on which file types caused your problem (e.g., PDF, .mp4, RAW images, etc..

• Windows 10/11 (File Explorer): open the folder → click View (or the three‑dot menu) → choose Details or List.
• Or right‑click an empty area in the folder → View → Details (or List).
  Expected result: Explorer stops generating thumbnails and becomes much snappier.

• File Explorer → three‑dot menu → Options → View tab → check "Always show icons, never thumbnails" → OK.
  Note: this makes all folders show icons only (no previews) until you undo it.

• In Explorer press Alt+P to toggle the Preview pane off. This prevents Explorer from loading file previews when you select a file.

• Right‑click the folder → Properties → Customize tab → “Optimize this folder for:” → choose General items (or Documents) → check “Also apply to subfolders” → OK.
  This reduces Explorer’s attempt to use heavy thumbnailing logic for folders that aren’t media libraries.

• Easiest: Run Disk Cleanup → select C: → check Thumbnails → OK → Delete files.
• Advanced (PowerShell): I can give you the safe commands if you want (requires restarting Explorer).

• Temporarily move video/RAW files out of the folder and reopen it — if Explorer becomes stable, a specific file or a bad codec is likely the cause.
• Try opening suspected media in VLC (it uses its own codecs) — if thumbnails for that file cause issues, avoid generating thumbnails for that format or install updated codecs.

• Run System File Checker and DISM if crashes persist: open an admin Command Prompt and run sfc /scannow and then DISM /Online /Cleanup-Image /RestoreHealth.
• If you want, I can walk you through those commands.

• Give the Disk Cleanup / PowerShell thumbnail‑clear commands, or
• Walk you step‑by‑step (I’ll tell you exactly where to click) for your Windows version, or
• Scan a folder you point me to (or an uploaded list) and flag likely troublemakers (large videos, RAWs, etc.?