When i click on a video file or windows media 6.4 or cinatagrapher i get an error message that says 'A device attached to the system is not functioning' it used to pop up a message after that saying theres a problem with quartz.dll and i think mentioned kernal32.

Any ideas what to do?

This is what i did that could have caused this. I installed WinDVD and a mpeg2 player and codecs from this link http://www.elecard.com/download/#mpeg2decoder

Please, please. If any one has any idea, please help.