u haven't specified your OS, but seems like your Icon cache are getting corrupted which happens now and then. kuna hii program inaitwa 'TweakUI' inaRepair user interface,, download it here for windows
XP ((((
http://download.microsoft.com/downl...a6-b352-839afb2a2679/TweakUiPowertoySetup.exe)))).
When the download is finished, double click on it, this should install it. When installed, Click
Start,
All Programs,
Powertoys for Windows XP, click
Tweak UI.
When
Tweak UI is loaded click on
Repair then on
Rebuild Icons and click
Repair, then
Apply and
Ok...
for Windows Vista and Seven, read on this Ultimate Windows Tweaker (
Ultimate Windows Tweaker, a TweakUI for Windows 7 & Vista | The Windows Club)