Remove image and media previews

1) Open a command window (Start->Run, type in 'cmd' hit enter)
2) To remove image preview, type and hit enter
regsvr32 /u shimgvw.dll
3) To readd image preview, type and hit enter
regsvr32 shimgvw.dll
4) To remove media preview, type and hit enter
regsvr32 /u shmedia.dll
5) To readd media preview, type and hit enter
regsvr32 shmedia.dll


Taken from: http://www.tweakxp.com/article140114.aspx