From the latest insider build windows 11, I am not able to use Win + R mspaint.exe as the new Microsoft Paint app is available pre-installed. Somehow I thought uninstall and reinstall the app will solve the issue (old windows 10 behavior , from optional features or from store you can install paint after uninstall) but it is not so. I see the paint app available to other user's logged in to the PC, only my login where i uninstall seems to be affected that I can't re-install back the paint app. I did a couple of workarounds, could get the old executable of mspaint.exe and put it in system32 folder at the moment as a workaround and also i am able to bundle up the new Microsoft Paint app and able to install it from the new microsoft store preview as workaround. I had to do these workarounds as the new Paint app is not available in the new Microsoft Store preview or in optional features, I want to report this issue for Windows 11 Pro.
