you can use ccleaner to see all the processes that are scheduled to run at bootup, many of which can be removed.
You can use a program called registry mechanic to organize and cleanup your registry for faster boots.
And you can use a program called diskeeper to defragment your MBR, and system files. Diskeeper makes the biggest difference, IMO. It's amazing what kind of speed a proper multi-pass defrag can restore.
