Have to agree with the previous post : codecpacks only do more damage than good. Had so many unpleasant experiences with them I will never use them again.
All you need is the DivX codec, the Xvid codec, a DVD player software (like PowerDVD or WinDVD) so that you can see mpeg2 movies and play ac3 audio and mpgaudio.ax filter registered so that movie files with ac3 sound could be played. The AC3 filter is also a solution but it has a greater CPU load and may cause stuttering. That's it. Never needed anything else. (well, maybe the Indeo packs as they don't come with WinXp by default)
If you ever need another codec, go here and install it manually:
Code:
http://mirror01.users.i.com.ua/~video/