What are the specs of your current computer?
Here's mine, though my machine is beyond what's needed for EQ2 and can run a game like Rift at max everything during a raid situation:
--AMD Phenom II x4 955 Processor (Quad Core, ~3.2 GHz)
--ATI Radeon HD 5700 series (1GB)
--Win XP 64-bit
From my personal experience, the biggest things that will help with performance will be the video card and memory. Sometimes that traps you into the pitfall of needing to upgrade your motherboard and CPU to accommodate newer hardware types (that depends on how old the motherboard is). I slowly upgrade mine every couple of years as prices come down on better pieces since there's always something new coming out that pushes down the pricing of "older" hardware.
It really depends on your current system so once we know that hopefully we can see if there's anywhere to improve. :) Also, have you tried EQ2 again lately to see how your system currently handles it? If you've updated it within the past 3-4 years you might not even have to worry.
edit: Another suggestion, we do have a forum for computer advice that Kaolian (our resident computer genius) covers, and maybe you can get some help there as well: http://eq2.zam.com/forum.html?forum=25 Edited, Jul 31st 2011 11:01pm by Cyliena