I am having trouble installing SP3 for Win XP Pro. I can download it and it starts to install, about 3/4 of the way through, it says it has to abort and goes through a uninstall. I have tried with no success about 3 times. I have closed all running programs, antivirus, networking, internet, anti spyware, etc. Any suggestions would be appreciated. I have a homemade system using an ASUS Mobo with a P4 and 1 gig of ram.

What was the specific error message? See Steps to take before you install Windows XP Service Pack 3 (http://support.microsoft.com/kb/950717).