Windows media player error in Vista

I am using Windows Vista 32 bit and when trying to launch Windows Media player, it gives me an error,
Instruction at 0x762794c4 referenced memory at 0x3f800000.
The memory could not be read”

This error occurs when I tried playing an .AVI movie, that I downloaded yesterday. I don’t think this is caused by a virus.
I had a full scan using my AVG Antivirus,and no threats were found. I cannot use the system restore, since I disabled system protection on my hard drives.
Can someone help me regarding this problem?
