XP has stopped playing videos

[gsf600y]

I'm running XP Pro.

Recently, if I play any videos (AVI/DIVX/XVID/etc), the program I try to play them in crashes (Winamp/WMP/Media Player Classic).
I'd installed a couple of DVD burning products recently, which might have caused it, but I've uninstalled them now.

I've reinstalled WMP, Media Player classic, and also K-Lite codec pack.

Anyone got any ideas? You're my last resort before I reinstall Windows, which I really don't want to do!

Thanks

 

[gsf600y]

Only thing that appears in Event Viewer is the application error for Winamp or Media player etc, and that only says:
Faulting application whatever.exe, version x.x.x.x, faulting module unknown, version 0.0.0.0, fault address 0x00000000.

I'll try out the repairing of XP option I think - I've spent long enough reinstalling all kinds of things now (drivers/applications/codecs).

Thanks for looking though guys, and thanks for instructions northboy