Error message when using Win Media Player 12 while downloading

HELP.

I cannot view any mpg files as when I try to download them I get the error message : windows media player error while downloading..

When I go into Microsoft Fixit area, and run it, it says it is fixed but it is not.

HELP..what is going on??? My computer seems possessed..

I also ran a scan using my Kapersky Pure antivirus and it came back NO VIRUS..NO PROBLEMS..NO MALWARE