Is there a problem with Divx player and Windows 7?

the best decoder is ffdshow and the best player in my opinion is media player classic home cinema
all found in the k-lite codec pack...plays practically anything and low on resources

Yes, you can actually download Divx codecs for Windows Media Player, this way you have can play Divx files withouth using Divx Player.

You're computer is probably laggy because Divx has an autoupdate service which connects to the internet automaticly.