Mysterious gray square outlines on certain desktop icons?
Solution 1:
The MS technet says that happens if the icon is scaled up or down.
Similar issues were fixed by refreshing the desktop by right-clicking on the desktop and choosing "show desktop" or "refresh"
If you have Windows 7, Pbergonzi from Cnet suggests:
Right-click Desktop → View → Change Large icons to Medium icons or Small icons.
Solution 2:
Just Right-click Desktop->View->Change Large icons to Medium icons or Small icons then refresh the desktop and you are done.