Without knowing what player you used here are a list of players that have different strengths and weaknesses.

Windows Media Player 10

Real Player

Quick Time Player

DivX Player

Avi Preview Player

All are available with a quick search of the net and all have FREE versions. Some like the DivX Player include extended Codecs.

Correct color problems with the Player Color controls.

Lagging is usually a sign you could use more RAM, Memory. Please don't confuse this with Your Harddrive space. Or you could try watching while shutting down nonessential programs..shutdown limewire or any other D/Ling service you are using while watching the movie.