Windows Update

[Gary]

When I try to go to the windows xp update page all I get
is a message that says "Thank you for your interest in
windows update. Windows update is the online extension of
windows that helps you get the most out of your computer.
You must be running a Microsoft windows O.S. in order to
use windows update." Does anybody know how to fix this.
I think it's a reg. thing but I'm not sure. Using Windows
XP Pro. Thanx