Dude, you might want to turn some services on. You might try to leave the DHCP service and the other "basic" networking services on and see what happens. If you disable DHCP and then go to your network connections and try to Refresh (obtain new IP) it will give you an error.
On my first install of XP I had about 1:30 min bootup, most of the time was spent at the bootup screen. I recently formatted, setup XP the same I had before, now my bootup is about :30 secs and little to no time is spent at the bootup screen. I have no idea what the hell kept it from booting fast before, probably a hidden command somewhere.
When all else fails, format and re-install is the best bet. Just remember the services too, those are important. If you don't know for sure about a service, set it to manual and it will run when you need it to. If you're wondering, I have only 8 services on Automatic, and on initial bootup, only those 8 are used.
Good luck man.