Definitely more RAM...(
http://www.ramseeker.com/pc/index.php). I did a bit of research on Windows memory/virtual memory/performance issues and came up with this list...
Download the latest drivers for your Video/Graphics card. (Unfortunately many cards are maximized for gaming. Drop the hardware acceleration setting down a notch or two. If it improves performance you have a driver issue.)
Keep the allocated RAM down to the default 55%
Set the Scratch disk to a drive other than the system drive, and preferably a fast one which has loads of free space.
Set Windows Virtual memory to max and min = 4GB
Search for and delete all .TMP files and Defrag all disks (regularly).
Empty the Windows Prefetch folder (regularly).
Keep your fonts list to a minimum and check for any dodgy ones.
Same with the plug-ins.
Set Bridge to "Cache all subfolders" and let it run all night (you only need do this once).
Hope this helps. CS2 is a fantastic program, and well worth the effort of getting it to run properly.