If you have SP1 or SP2 .. put it on a cd
before you start.. that will avoid getting online without any updates.
Of course, if you plan to install "over" your current XP installation rather than formatting, then you can just run the service pack from the harddisk afterwards.
Or there's always slipstreaming:
http://www.cableforum.co.uk/board/sh...ad.php?t=16034
Which is easier still.. and should work with your OEM cd.