Why are more and more Windows apps no longer working on Windows 10?

About a month ago, I noticed that several Windows apps had stopped working. Among these apps was the Microsoft Store, as well as the Weather app and “Solitaire & Casual Games.” About a week later, the “Media Player” and “Game Bar” suddenly stopped working as well — even though these apps had been functioning just fine beforehand.

The problem affects only Windows apps. All other programs can be installed, run, and—if necessary—uninstalled without any issues.

All my research into the problem has yielded no results. I wanted to try repairing the apps, but that option isn't available to me. I only have the “Reset” option. I attempted to reset them, but I simply received an error message stating that the app could not be reset. Initially, the whole situation looked like a virus to me.

However, virus scans—conducted using both Windows Defender and a separate antivirus program (which I installed specifically for this scan, and which had helped me resolve a virus issue years ago)—came up completely clean. Today, the “Movies & TV” app has also stopped working.

For all the apps that aren't working, you see this weird black bar:

The date visible in the image corresponds to the date from which the program stopped working:

I tried manually reinstalling Media Player by downloading it from the Microsoft Store website, but the installation failed.

I don't know if this has anything to do with my problem, but whenever I try to open an audio or video file now, I see this strange “Microsoft WinRT Storage API” appearing in place of both Media Player and “Movies & TV.” Until the day before yesterday, it only appeared in place of Media Player. This is what it looks like:

I tried running DISM and SFC many times, but it wasn't helpful. I have used wsreset.exe to fix Microsoft Store but got the error mesage:

I installed Windows Repair from Tweaking.com and tried to repair the Windows apps with it:

After I pressed "Start Repairs," a CMD window—or whatever it's called these days—popped up; however, various error messages kept appearing repeatedly within it. Eventually, I aborted the process, but the damage had already been done, and even more Windows apps were corrupted. So the result was the exact opposite.

It now appears to affect several codecs as well. For instance, the webp codec suddenly stopped working, too.

The easiest, most general way to repair such multiple errors is to download the Windows 10 ISO and Create Windows 10 installation media. Then perform an in-place upgrade, which should keep all your files and applications.

Reinstalling Windows, keeping files, is usually fairly fast and painless, taking less than a half hour, but that said, before performing this, it would be good practice to make a complete disk image, lest something go wrong.

If that does not remedy the issue, then you Windows profile might be damaged. Test that by creating a new user account. Log in as that user and see if Microsoft Store, Media Player and other apps work. If so, then you face the nuisance of migrating to the new account, as repairing a broken account is nontrivial. In my experience, it most often does not succeed.

Another possibility is a failing main drive, corrupting the OS. Check drive S.M.A.R.T. stats.