Windows Updates Help

Wassup kids, I got a lil problem, I need to download updates on this laptop that need to be installed on my PC at home.

I've got a fairly capable custom PC and a decent laptop I got with Orange. As an added bonus, I got free mobile internet with Orange through a usb dongle. The dongle works so well (easily 250kb/s) that for the past year I've opted to use it rather than pay for home broadband.

I usually use my comp for offline activities (like Playing games or Uni. assignments) and light online activities (like emails, research, Facebook, MSN, etc...), so although Im limited to 3gig a month download limit, my dongle has done me well. My laptop on the other hand, has freedom of movement, I use it for heavy download jobs from Uni library and friends' houses to be later uploaded to my pc.

Because of this setup, automatic updates are a bitch on my PC coz I try to limit my net traffic to 100mb a day give or take, and that doesnt agree with the bigger updates. To top it all off, ive just been forced to reinstall my operating system, back to square 1. What I wanna know is if I can get stand-alone automatic updates, downloaded on this laptop (Windows Vista), upload and install them on my pc (Win XP Sp2).

I dont want sp3.