There is a hidden icon cache file in your windows directory, ShellIconCache, which contains a copy of all the default desktop icons. It sometimes gets corrupted. If it does, your icons will go all black or they may display the wrong icons. If this happens, delete it and reboot. NT (& Win9x) will repopulate the cache with the default icons. To delete the ShellIconCache:

• at a command prompt, change to the %SystemRoot% folder
• remove the hidden attribute from the file:
  type attrib -h shelliconcache and press ENTER.
• delete the file:
  type del shelliconcache and press ENTER.
• logoff and backon and the default icons should be restored.

This tip applies to all versions of Windows including Windows NT, Windows 2000, and Windows XP.

If the default icons were deleted from a Windows NT desktop, they can be recreated from the registry. See Q151723