XP SP2 update computer won't boot now

[Tony]

Well, I just downloaded the update and when I tried to
restart the computer it only makes it to the Windows XP
screen and then it restarts again. I tried using safe
mode and last configuration that worked and it does the
same thing. Now what?

 

[Jupiter Jones [MVP]]

Tony;
Perform a Repair Installation:
http://www3.telus.net/dandemar/repaxp.htm

When you are ready for SP-2, follow the Service Pack Installation
Checklist:
http://www3.telus.net/dandemar/spackins.htm

 

[Hans-Georg Michna]

Well, I just downloaded the update and when I tried to
restart the computer it only makes it to the Windows XP
screen and then it restarts again. I tried using safe
mode and last configuration that worked and it does the
same thing. Now what?

Tony,

you already got good advice. If the problem persists, please
have a look at http://www.michna.com/kb/WxSP2.htm for a few more
outlandish causes like problems with Athlon 64 processors and
drivers.

Hans-Georg