You need to rebuild the Windows ICON cache. I know the commands to do this, but if you make an error, it could make your computer a paper weight.Search the net for "rebuilding the Windows ICON cache" and it should get you the results you need.
Surely you mean it's nothing an OS reinstall wouldn't fix. Paper weight would require damaged hardware.
...I am always nervous about providing a string of "run" commands where I am not the one typing them in. Some of those commands can do serious damage with a simple typo.