old computer vista video playback problem

[mikee]

My sisters bf asked me to fix his computer because he got a really bad virus but it was so messed up I couldn't even use windows explorer. He said he wanted to try vista on it . So now that vista is set up I downloaded k-lite mega codec pack but now all wmp says when I try to play a video is windows media player encountered an error and the files don't play

Here's the specs of his computer

Amd athlon xp 2700+
2GB ram
160GB HDD and 250Gb HDD
Geforce Ti4200 Graphics
Soundblaster live 5.1 sound card

 

[KSoD]

Do the videos play in any other media player?

 

[mikee]

the only other one is winamp which won't play either

 

[KSoD]

So if it wont play in any media player there is something wrong with the file not the player.