Aborting an update?

I was just hoping to shut down and restart my computer, but now it is doing
automatic updates, I guess. There is a message of "Do not turn off or unplug
your computer; it will turn off automatically" that alternates with "updates
are being installed (3 of 8)..." This has been going on for two hours (stuck
on the same "3 of 8" message). Can I abort this process safely, and if so,
how? I have a zillion things I need to get done at work today and cannot
afford to have my computer tied up like this.

I would appreciate any one who can advise me what to do, but not in techie
jargon, please. (I am just a user of this computer and do not know
terminology nor what all is installed on this computer.) We do not have any
in-house experts. All I know is that it is Windows XP.

Thank you.

Ruth