File associations in Windows 10 reset due to Microsoft’s policy reverting certain file types to default apps after updates or system changes. 2. To fix this, go to Settings > Apps > Default apps > Choose default apps by file type and set each extension (e.g., .pdf, .mp3) manually. 3. Set your preferred browser as default for web files to prevent Edge from reclaiming .html or .pdf associations. 4. Use third-party tools like Default Programs Editor or OpenWithView to backup and restore associations or reapply them in bulk after updates. 5. Advanced users can disable the reset via Registry by navigating to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts, deleting the UserChoice key for the affected extension, re-setting the default, and optionally denying write permissions to prevent future changes. 6. Uninstall conflicting software, especially bundled or optimizer tools, that may interfere with associations. 7. Microsoft acknowledges this behavior as intended to improve user experience but has reduced it in newer updates, so staying updated helps. 8. After every Windows update, verify default apps through Settings, not right-click menus, and consider pinning preferred apps for easier access; on managed devices, contact IT if Group Policy enforces resets. This issue is persistent but manageable with proper setup and maintenance.

If your Windows 10 file associations keep resetting—meaning apps like PDFs open in a different program, or media files suddenly switch players—it’s a common but frustrating issue. Microsoft introduced a policy in Windows 10 that resets certain file associations back to Microsoft-recommended defaults after major updates or sometimes even after a reboot. Here’s how to understand and fix it.

Why File Associations Keep Resetting

Microsoft automatically resets file type associations for certain extensions (like .pdf, .html, .jpg, .mp3, etc.) to default Microsoft apps (Microsoft Edge, Groove Music, Photos, etc.) under these conditions:

• After a Windows 10 feature update (e.g., 21H2 → 22H2)
• When Windows detects a system change or repair
• Due to Group Policy or system policies overriding user settings
• Sometimes triggered by third-party software uninstallation

Even if you manually set Chrome as your default for .html or VLC for .mp4, Windows may revert them.

How to Stop File Associations from Resetting

1. Set Defaults Properly Using Windows Settings

Don’t just right-click → “Open with.” That doesn’t always lock in the association permanently.

? Do this instead:

1. Go to Settings > Apps > Default apps
2. Scroll down and click "Choose default apps by file type"
3. Find the extension (e.g., .pdf, .mp3, .jpg)
4. Click the current app and select your preferred program

? Make sure to set each file type individually. Don’t skip any.

2. Lock in Browser & Common App Defaults

For web-related files (.html, .htm, .url), also set your browser as the default:

• In Default apps, click on Web browser
• Select Chrome, Firefox, or your preferred browser
• This helps prevent Edge from reclaiming .html/.pdf associations

3. Use a Third-Party Tool (Recommended for Power Users)

Tools like Default Programs Editor or OpenWithView let you export your current associations and reapply them if they reset.

Alternatively, "Restore File Associations" from Ninite or bulk association tools can help reassign en masse after an update.

Example: After a Windows update, run a script or tool to reapply your preferred defaults quickly.

4. Disable Automatic Reset via Registry (Advanced)

You can disable Microsoft's "revert to defaults" behavior using the registry:

?? Warning: Editing the registry can be risky. Back it up first.

1. Press Win R, type regedit, and press Enter
2. Navigate to:
   HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts
3. Look for the file type causing issues (e.g., .pdf)
4. Inside .pdf, delete the UserChoice key (this allows you to re-set the association cleanly)
5. Re-set your default app in Settings
6. Optional: To prevent future resets, some users set permissions on the UserChoice key to deny write access (advanced)

Alternatively, use a .reg file to lock preferences.

5. Check for Conflicting Software

Some apps (especially free software bundles or outdated installers) reset associations on install/uninstall.

• Uninstall suspicious or unused software
• Avoid "cleaner" or "optimizer" tools that mess with defaults
• Reinstall your preferred apps (e.g., Chrome, VLC) and set them as default again

What Microsoft Says

Microsoft acknowledges this behavior and says it’s meant to "improve user experience" after system changes. However, they’ve reduced the frequency in recent updates (Windows 10 21H1 and later). If you're on an older version, updating may help.

Final Tips

• After every Windows Update, double-check your default apps
• Use Settings > Apps > Default apps — not right-click context menus — to set associations
• Consider pinning your preferred apps to Start or Taskbar so switching back is easier
• If you're on a managed work device, Group Policy might be forcing resets — contact your IT admin

Basically, Windows 10’s tendency to reset file associations is annoying but manageable. The key is setting defaults through the correct menu and staying vigilant after updates. With a little maintenance, you can keep your favorite apps in control.

The above is the detailed content of Windows 10 file associations keep resetting. For more information, please follow other related articles on the PHP Chinese website!