Hello and welcome to the forum
You’re using Windows 7 and Microsoft stopped supporting Windows 7 at the start of this year. It’s now regarded as an obsolete operating system and the developers simply can’t support it or test against it or fix any bugs that happen with a Windows 7 system.
The obvious thing for you to do is to update your PC to Windows 10. This may not be possible or desirable if it’s an old or not very powerful PC.
Another possibility is to try to use an older verson of krita, one that did work fine with Windows 7.
Here is a listing of previous versions:
As a suggestion, I’d try 4.2.8 (or earlier) which was released in November 2019.
You’d need the -x64 or -x86 setup.exe depending on whether you have a 64-bit or 32-bit PC.
Bear in mind that the old versions have unfixed bugs which were later fixed for the current 4.3.0 version