Solved Cannot set XnView MP as default image viewer in Windows 11 (25H2) – associations fail even with admin, registry, and “Open with” methods

yastil · Feb 17, 2026

Hello,

I have a problem setting XnView MP as the default image viewer in Windows 11 (25H2), and nothing I try seems to work. The system keeps refusing the file associations.

Problem description:
When I try to set file associations in XnView MP (for all image types), the program shows an error like: “Failed, try with administrator privileges,” even when I run it as administrator.

What I have already tried:

Running XnView MP as Administrator and attempting to set associations inside the program.
Looking for the Integration / File Associations section (not present or not working in my version).
Setting defaults via Windows Settings:
Settings → Apps → Default apps →
- Set defaults by app (XnView MP)
- Choose defaults by file type (.jpg, .png, .bmp, .gif, .tiff, .webp, etc.)
Right-click method:
Open with → Choose another app → XnView MP → “Always use this app” (does not work).
Importing a custom .reg file assigning all image formats to XnViewMP.exe (saved without BOM, imported successfully).
Restarting the system after registry changes.
Verifying the correct program path:
C:\Program Files\XnViewMP\XnViewMP.exe

Result:

Windows still ignores the associations and images do not open in XnView MP.
Some formats (especially JPG/PNG) seem to be forced back to the Photos app.
Even with administrator rights, the associations cannot be permanently changed.

Question:
Is there a protection mechanism in newer Windows 11 builds that blocks changing default image associations?
Is there any official or reliable method to globally set XnView MP as the default viewer for all image formats without Windows resetting or ignoring the associations?

Thank you for any technical advice.

Josey Wales · Feb 17, 2026

I would make sure that there is no other program set as default for these file extensions( .jpg, .png, .bmp, .gif, .tiff, .webp. )I use XNnView standard and do not have this issue.

OAT · Feb 17, 2026

@yastil,

This has always worked for me.
Right click on photo, properties, Change and select the app/program.

yastil · Feb 17, 2026

Hello,

Thank you for your suggestions.

I want to clarify that I am currently using Total Commander version 9.51.

Because of this, some of the newer options like “Custom associations” are not available in my version.
As a result, even though I’ve tried changing the Windows default apps, using registry edits, running XnView MP as administrator, and using “Open with → Always use this app,” Total Commander 9.51 still opens images with the Windows Photos app on Windows 11 25H2.

So the issue seems to be related to the combination of Windows 11 protecting default image associations and older TC version 9.51, which cannot override these defaults.

I wanted to clarify this so that suggestions are relevant to my version of Total Commander.

Thank you.

HeavyHemi · Feb 17, 2026

yastil said:
Hello,

Thank you for your suggestions.

I want to clarify that I am currently using Total Commander version 9.51.

Because of this, some of the newer options like “Custom associations” are not available in my version.
As a result, even though I’ve tried changing the Windows default apps, using registry edits, running XnView MP as administrator, and using “Open with → Always use this app,” Total Commander 9.51 still opens images with the Windows Photos app on Windows 11 25H2.

So the issue seems to be related to the combination of Windows 11 protecting default image associations and older TC version 9.51, which cannot override these defaults.

I wanted to clarify this so that suggestions are relevant to my version of Total Commander.

Thank you.

Any reason why you're not using the latest version 11.56 released last August?

Total Commander - home

Homepage of Total Commander, a file manager replacement for Windows 95/98/NT/2000/XP/Vista/7/8/8.1/10/11

www.ghisler.com

OAT · Feb 17, 2026

yastil said:
Hello,

I wanted to clarify this so that suggestions are relevant to my version of Total Commander.

Thank you.

Total Commander 9.51 does not support Win 11.
A lot of win32 legacy code has been dropped in 25H2 as well, this probably explains the issue you are having.
Have you tried 11.56? It seems to support win11 or you haven't switched because it's shareware?

yastil · Feb 17, 2026

OAT said:
Total Commander 9.51 does not support Win 11.
A lot of win32 legacy code has been dropped in 25H2 as well, this probably explains the issue you are having.
Have you tried 11.56? It seems to support win11 or you haven't switched because it's shareware?

Hello,

Thank you for your explanation.

I understand now that Total Commander 9.51 is no longer compatible with Windows 11, especially with build 25H2, where some legacy 32-bit code was removed.
That explains why the image associations did not work correctly.

I have now switched to Total Commander 11.56, which fully supports Windows 11, and XnView MP works as expected.
Therefore, the issue has been resolved, and no further troubleshooting is needed.

I appreciate your guidance.

Best regards,
yastil

Helmut · Feb 17, 2026

yastil said:
Some formats (especially JPG/PNG) seem to be forced back to the Photos app.

Even with administrator rights, the associations cannot be permanently changed.

Same here, it is not only XnView it also happens with IrfanView.
Sometimes, after a Photos App or Windows update.

Not frequent enough to worry about, I just change them back.

I do not have Total Commander.
Not so sure of it being solved.

OAT · Feb 17, 2026

Helmut said:
Same here, it is not only XnView it also happens with IrfanView.
Sometimes, after a Photos App or Windows update.

Not frequent enough to worry about, I just change them back.

I do not have Total Commander.
Not so sure of it being solved.

I found the Photo APP way too intrusive and have removed it from my systems.
Like you, IrfanView is my program of choice.

garlin · Feb 17, 2026

You can try disabling the User Choice Protection Driver (which ironically blocks user choices...):
Enable or Disable UserChoice Protection Driver (UCPD) in Windows 11 and 10

Solved Cannot set XnView MP as default image viewer in Windows 11 (25H2) – associations fail even with admin, registry, and “Open with” methods

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