Vista - Media Player, Not playing

An odd thing happened the other day, I shut down my pc after watching a few movies. When I started it the next day Media player would no longer play video files, or audio files. When I click on a file to play, media player loads but it just sits there, and the wee Widgit on the side bar shows that it's using 50/60% of the processor.... Ive looked into reinstalling the player bur most sites state that its basicly built into vista and a reinstall of the OS will fix it, but thats to much hassle. The audio and Video files work on other players, I.E. Zoom Player and Quicktime.
But I Love to use Media player, The way you can just select several Vids, right click and add to player list.
I've downloaded all the updates that windows update suggests,

Anything you guys can suggest will be greatly appreciated

Thanks In Advance...
Kricky

Why not try a system restore, since you said it was working before, its helped me a lot when something goes wrong with my pc, which will restore your system to an earlier time, its like a time machine, just go to-Start-Type in start search: system restore, click on that-then click on: choose a different restore point-then just click on an earlier time before this problem happened, It'll usually fix your problem, has for me.
Tell me how it goes,


~LordJohnx3