After installing some new MPEG editing programs and some codex, my system refuses to playback MPEG2 files in the new Mediaplayer 7.1.
I have no idea what program caused this, but by now I've already deinstalled almost any MPEG related software from my computer, reinstalled Media Player and WinDVD and still it wont work anymore.
Loading any MPEG file in Mediaplayer 7.1 will result in Mediaplayer trying to download some codex from Microsoft, failing and then crashing. Trying to load a MPEG2 in TMPGEnc for re-encoding will crash TMPGEnc. However, I can still load and play files in WinDVD without problems. When I remove Mediaplayer 7.1 the "old" Mediaplayer will also try to download a codex but after failing it will play the file anyway.
Any ideas?

this is on Win 2000