The simplest solution is probably to just reinstall Arduino. Make sure you get the EXE installer, not the Windows Store version.
If you want to dig into this problem, the next step would involve looking to see what's actually in that C:\Program Files (x86)\Arduino folder. Every copy of Arduino is supposed to have a "lib" folder, and inside that folder should be "version.txt". The installer says it doesn't see that file. Can you see it if you look in that folder?