Problem with Service Pack 3 Upgrade

[Strider]

I'm on vacation in Florida at my parents house enjoying the warm weather. Anyways, I'm trying to spruce up my father's computer and I have run into a major snag I can't get Windows XP SP3 to install. I have tried 2 times and both of those times it'll go all the way up to the point of cleaning up install then the computer will reboot then it will restore back to SP2. Here are the specs to the computer :
Intel D845GLAD Motherboard
1800 P4 Celeron CPU
1 GB of Memory
1 - 60 GB Hard Drive
1 - 20 GB Hard Drive

I'm thinking since I only have 9 GB of Drive Space on my Boot Drive that it might be causing the problem, BUT I think I'm going to have to delete the SP3 download since I think that might be corrupted (I don't know how to do that) plus free up more disk space on the boot drive. Of course I could be wrong in thinking this is the problem and I really don't want to keep trying to install the SP3 upgrade without fixing the problem for one it's takes a long time when it fails, two it's hard on the computer that's starting to show it's age and three I'm on Vacation. Any help in this problem will be greatly appreciated.

[rjfvillarosa]

Not sure if this can help you but take a look at the link in this thread:
http://forum.pcmech.com/showthread.php?t=203918

[EzyStvy]

Before you start
Important Apart from the hard disk space mentioned in this article, the computer’s first primary system partition must also have 30 MB of free hard disk space.
http://support.microsoft.com/kb/947311

Steps to take before you install Windows XP Service Pack 3
http://support.microsoft.com/kb/950717/