[paroh]

Start | Run REGSVR32 /u SHMEDIA.DLL

this will deregister Windows Media DLL wich assecces File info for details/thumbnails etc

Test your issue/problem WiTHOUT rebooting - then if it goes away - Reboot and try again - post results

in order to ReRegister, in case no luck;
REGSVR32 /i SHMEDIA.DLL