Need Help

For some reason I can not update to windows vista SP1 with windows
update; therefore, I decided to download SP1. I download SP1 64bet and
my PC did not support it. Then, I downloaded the 32bet. Unfortunately
both of them did not work. I found out that my system is X86-based PC.
So now I have no idea what to do. Can some one help please.

Microsoft Windows XP
Home Edition
Version 2002
Service Pack 3