Default apps reverting to MS defaults after every restart

Question

I am running Windows 10 Home, Version 22H2. My system is fully up to date.

For the past several weeks, every time I restart my system, default apps reset to Microsoft programs for jpg, avi/mp4, browser, and pdf. I use Picasa for images, VLC for videos, Vivaldi as my browser, and Acrobat X for pdf. None of these programs has been changed for months (although there may have been a recent VLC update). The main issue is pdf

Steps I have taken so far, based on researching this issue online:

1. Checking for updates and restarting. Always my first troubleshooting step. I considered the chance that there could have been a problematic update, but Windows won't let me roll back. That said, there seems to be a new update at least once a week, and the issue persists.
2. Manually setting "Choose default apps" in settings. They do not survive the next restart. Oddly, Windows does not set Outlook 2016 as my default email handler and resets it to a gray "+." There is also no entry on this list for pdf.
3. Choosing default apps by file type. I hate how long this list is. Still, scrolling down and finding "pdf" in the list allows me to choose Acrobat but it doesn't stick.
4. Choosing default apps by protocol. Another long list of protocols I've never heard of. There is no option here for pdf.
5. Select default pdf handler in Acrobat preferences. I've tried this several times, Acrobat is the only option but it also does not stick.
6. Run sfc /scannow and DISM ScanHealth and RestoreHealth. No problems reported.
7. "Automatically save my restartable apps..." I've tinkered with this setting based on some online comments, but it has no effect.
8. Several sources have suggested I modify the registry. These sources focus on changing registry entries for Microsoft Edge, a program I do not use that is hijacking the pdf protocol. They suggest adding a "NoOpenWith" string to program key "AppXd4nrz8ff68srnhf9t5a8sbjyar1cr723" But that key does not exist in my registry, and I have not seen instructions for how and where to create it.

Is there something I'm missing? It's really frustrating that Windows hijacks my default apps every single time I restart.

What I'm really trying to avoid is having to reinstall Acrobat, which I purchased 10 years ago but I haven't been able to find my product key.

Answer 1

Hi ]chris[

Thank you for posting in Microsoft Community.

I understand the frustration you are experiencing with default apps resetting on your Windows 10 system. Since you have already tried several troubleshooting steps without success, let's focus on resolving the issue related to PDFs and default apps.

> Disable Microsoft’s Default App Reset Behavior

Windows sometimes forces default apps back to Microsoft programs after updates. You can try disabling this behavior:

Open Registry Editor (Win + R > type regedit).

Navigate to:

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Explorer

If Explorer doesn’t exist, create it.

Inside Explorer, create a DWORD (32-bit) Value named:

NoOpenWith

Set its value to 1.

Restart your PC and check if your default apps persist.

> Prevent Windows from Resetting Defaults via Group Policy

If you're using Windows 10 Pro, you can try this:

Open Group Policy Editor (Win + R > type gpedit.msc).

Navigate to:

Computer Configuration > Administrative Templates > System > Default Associations Configuration

Enable "Turn off Microsoft Default Associations".

Restart your PC.

> Lock Default Apps via Registry

Since modifying the registry for Edge hijacking PDFs didn’t work, try locking your default apps:

Open Registry Editor and go to:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts.pdf\UserChoice

Delete the UserChoice key.

Restart your PC and manually set Acrobat as the default again.

> Create a New User Profile

If your current profile is corrupted, Windows may not retain default app settings:

Open Settings > Accounts > Family & Other Users.

Create a new local user account.

Log into the new account and set default apps.

Restart and check if they persist.

Open Command Prompt (Admin) and run:

dism /online /Import-DefaultAppAssociations:C:\Path\To\DefaultApps.xml

Restart your PC.

Perform Repair in-place upgrade: This will reinstall your Operating System and will keep your files and apps. This will take some time depending on the computer performance and internet speed. You can follow the steps from this link: How to do a Windows 10 Repair Upgrade - Microsoft Community

Please let me know if this helps

Best Regards,

Lonex P.
Microsoft Moderator

Answer 2

Hi ]chris[

We haven't heard from you, so we assume that your issue has already been addressed. We will not be monitoring this thread moving forward so, if you need further assistance, please create a new thread to discuss these concerns by clicking this link: Create a new question (microsoft.com)

Thank you for understanding.

Regards,

Lonex P.

Microsoft Moderator