Automatic Update problem with SP1

Hello,

We recently upgraded our operating System from
Windows 2000 Server to Windows 2003 Server.
The 2003 server had been running OK for
a while. So, we performed the Automatic Updates,
and the first update was successful. Later,
Automatic Update wanted to install SP1.
We let the Automatic Update run unattended.
Now, our server never boots up. It displays
the Windows Server 2003 splash screen, then
a blue screen appears (with some text) and the
server re-boots. Unfortunately, the server
reboots so quickly, after the blue screen is
displayed, that we cannot read the message.

How do we prevent the computer from automatically
rebooting. so that we can read the blue screen message?

TIA,
Jacques