Cant update to lion 10.7.3!?

[ROFLAMOWLOL]

Ok so i have been trying to update my macbook OS X to Lion 10.7.3 because i am interested in xcode (app). but when i try to software update it says [ The Software Update Server (lotus.local) is not responding. Check to make sure your network connection is operating normally. If there are no issues with your connection, contact your network administrator for assistance. ]
Why??

Some info:
this is a school granted laptop

Processor 2.4 GHz Intel Core 2 Duo
Memory 2 GB 1067 MHz DDR3
Graphics NVIDIA GeForce 320M 256 MB
Software Mac OS X Lion 10.7.2 (11C74)
Serial Number 452016KBF5W

thanks
Josh

 

[Kaveman]

This is a large download 1.3 Gig, if your on a slow link then you may have troubles.
try support.apple.com/downloads/