That doesn't look like the full error message. It helps a lot if you can provide the full error message -word for word. That will help others to help you.
Everytime I try to use Windows Media Player it gives me an error message "Error Signature". I tried the fix from KnowledgeBase and that didn't work. What's next?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic