Icon issue

Yesterday I fixed an issue with certain icons (usually in different programs) that were completely black. I fixed the issue by deleting the ‘shelliconcache’ file in the Windows directory. Today, when I have any program, the ‘minimize, restore and close’ buttons (at the top right of screen) are garbled when the window is maximized. If the program’s window is slightly smaller than the full window size, there is no problem.

Any ideas?