Having too many temp files can also mess with Windows' ability to operate properly. Here's my little "regular maintenance checklist". It might help, along with what you're already doing. By the way, certain programs just leak memory like mad. What apps do you regularly run?
Maintenance Checklist:
-- Delete all temp files (c:\windows\temp\*.tmp, or on XP C:\Documents and Settings\username\Local Settings\Temp)
-- Delete temporary internet files (c:\windows\temporary internet files\*.*, or on XP C:\Documents and Settings\username\Local Settings\Temporary Internet Files)
-- If you use I.E., click on Tools, Internet Options, Delete Files, select "delete all off-line content", click OK
-- Click on Start, Programs, Accessories, Systems Tools, Disk Cleanup
-- Download
AdAware, check for updates, run it and remove whatever it finds
-- Download
Diskeeper and defrag
-- Download, update and turn on
SpywareBlaster and
SpywareGuard (or your spyware removal tool of choice).