prehistoricman wrote:screw codecs, go download
vlc.
VLC blows... not only is it slow to open, lags on pausing but some of their built-in codecs don't work for everything such as certain displaying inbedded subtittles or bugs with some dual-sub or dual-audio files.
Using VLC is like using AOL. It works for most things and is simple to apply... but it blows hardcore.
On a side-note, VLC's option to make your destop wallpaper play video is pretty cool. I admit I have VLC... I just don't use it bcz I prefer Media Player Classic for it's speed and reliability. Uninstalling your current codecs, Installing the CCCP codec pack and setting Media Player Classic as your default media player for your file types, takes less time than Installing VLC altogether.

But my opinion is kinda biased, VLC is a good tool... it just irritates me greatly... particularly the pause function always waiting 1 second before pausing. But yeah, if you want an easy solution, get VLC... Otherwise MPC + CCCP codec pack all the way (it's easier than you think)
VLC vs MPC:
http://www.digitalhome.ca/forum/showthread.php?t=92219