How many Windows patches can you put on an old XP computer?

I have an old XP computer that has been sitting unused for a few years so I decided I would get it cleaned up and put on all current Microsoft patches and then give it to someone.  I stopped counting at the automatic updates at 200 patches and that DOES NOT include huge patches for .Net and Windows Service Pack 3 and IE 8.   Of course then there is all the hard drive clean up of unnecessary files and registry cleanup and defrag the hard drive as well as updated virus protection and firewall.  What an undertaking that took me two days  but all went well with no problems so someday soon someone will have a new computer.