In news:50BB9073-52FE-481C-BB60-C657883FD4AA@microsoft.com,
Josh <Josh@discussions.microsoft.com> had this to say:

My reply is at the bottom of your sent message:

> For some reason, my Windows XP professional decided to turn on
> security updates. So it starts downloading a security update and I
> rebooted once it installed it. Now after the Windows logo appears and
> theblue loading bar appears, for a split second I think the logon
> screen appears and then the computer rebbots itself and the only way
> to get out of this endless loop, is to turn the computer off at the
> power point. I don't think anyone else has this problem. Please help!
>
> I have also tried to contact Microsoft by e-mail but becuase I can't
> even get Windows to boot, (I'm using someone elses computer) I can't
> find out my product number. I have also tried to reboot or start the
> computer in safe mode with the bare minimum but it also crashes and
> restarts.
>
> Thanks for the help in advance. Josh

If you can't access the OS and there's no specific error message the very
first troubleshooting step to consider is usually a repair installation:

Repair Installation of XP:
http://kgiii.info/windows/XP/general/xprepair.html

--
Galen - MS MVP - Windows (Shell/User & IE)
http://dts-l.org/

"My life is spent in one long effort to escape from the commonplaces of
existence." - Sherlock Holmes