This hotfix is for Vista not for Windows 7 thus you couldn't install this hotfix.For 7 you have to wait undefinitely time.
Try reset thubnail cache
Thumbnail Cache - Clear and Reset +restart
If this tutorial no help try reset thubnail manually -it strange but probably Disk Cleanup only empty cache files don't remove these files completetly thus clearing manualy cache files are more credible.
Run system in safe mode,navigate to
C:\Users\<your account>\AppData\Local\Microsoft\Windows\Explorer
and there you'll find 6 *.db files ->remove them + restart.System re-create these files after restart