It's been mentioned previously that the codec packs can get messy sometimes, but I actually have never had any problems with them in the couple years that I've used them on windows [no longer need them on mac].
I guess each to his own
FYI, if you're looking for the codec packs, try the k-lite codec pack -
http://www.free-codecs.com/index.htm
That's the one I'd recommend, although make sure to read the README, to make sure you don't install conflicting codecs.
Also, definitely stay away from the nimo codec pack - I ran into a few problems with those.
Catcha back on the flipside,
keyshawn