XP Professional fails to start after update

[art]

I need to add that the PC is a Gateway laptop.
>-----Original Message-----
>I did the standard update procedure for Windows XP
>professional edition. At the end of the update the
>option to restart was selected. On restart I get the
>black screen with the option to select Safe Mode, Safe
>Mode with Networking, etc, etc. No matter which option I
>select I get the Windows splash screen with the progress
>bar running, but it goes no further. I am hung forever
>on the splash screen.
>Incidentally, just prior to doing this update, I updated
>the Norton AntiVirus software and scanned for viruses.
No
>viruses were found.
>Any suggestions other then reformatting and reloading?
>.
>