Boot up error

[Reaper414]

So I upgraded from xp home to vista ultimate. Nice right? NOPE! I just had 87 updates downloadedand installed and when it went to reboot everything was going fine untill, it decided that it didnt want to boot and kept going through the boot cycle without even getting to the load screen. I don't think it is anything that I had done. I havent even made any changes to the system. I just reinstalled windows xp home to attempt the upgrade to vista ultimate. if anyone has any idea why it decided to be a jag off please let me know. I am tired of running xp home and after paying a lot of money I really would like my vista to work. my computer is a emachines w3052 with 1.5 gigs of ram, running two hardrives both 120g. my processor i think is 2. something gigahertz. i know my machine is capable of handeling it but i just need to know what the heck is going on. if someone could help me i would greatly appreciate it. oh and if it helps when it would go to boot up for a split second thered be some text and a black box outlined in white. if that is any help, because i just remembered it
Thanks
Gavin