64 bit Ultimate and gaming issue

I just upgraded from XP to Windows 7 64 bit ultimate. Everything seems to be running great except for my game. I play everquest 2. Now i have changed nothing else about the computer except for the OS and when it was on XP i had zero issues with lag and graphics. Now the lag is so horrid i can't play. A few specs about this beast i'm on: ATI radeon HD 3600 512 graphics 3 gigs of ram AMD athlon 64 processor 3200+ 2.00 Ghz Windows 7 Ultimate 64 bit for anyone that missed I installed latest graphics...then tried older graphics....just wondering what i'm doing wrong here if anyone can help.

Make sure your drivers are the very latest as they would be completely different from the drivers in XP and cause most of the issues for people upgrading.

Also check the game site itself for game patches, which are often released to fix issues with newer OSes.

I also found this but would only try it if updating your drivers doesn't resolve your problems ...
I'm not an online gamer so I haven't tried this myself but a quick search found THIS.

Seems like win7 64 is not supported... http://www.everquest2.com/gameinfo/faq#4info

Have you tried a clean install of the game?