Windows XP updates are not very important.
Just use a firewall, and antivirus, and don't use IE, and disable autorun. Then out-of-box XP SP3 runs just fine and is secure.
I always turn off autoupdates because:
1. Update-on-shutdown sometimes hangs and corrupts system.
2. They interfere with Anti-WPA. (remotely disabling Windows)
Updates might matter at multi-user installations or when there is no firewall.