simple windows update problem?

[Arbzask]

i have been using windows XP home edition for some time and have acumulated many service updates (patches) for windows using windows update. I wish to reformat my hard drive and re-install windows XP on the computer to iron up some gathering bugs, but i wish also to get my windows update downloads and put them on a seperate drive to install when the newe OS is installed, but i cant for the life of me find where the packages are kept. i can see them in add/remove programs but nowhere else, let alone copy-able to another drive. i only have a dialup connection so i dont really want to download 20+Mb of updates again.

thanks

ps, will xp home updates work on XP proffessional (bearing in mind that i will not use IIS on Proffessional)

[sdkfz]

My first thought was to order the service pack on cd, but I can not find it as a release on MS.com, my second idea, would be to try a friend with a broadband acess and a burner to copy the files. I am not at my home machine so could not search for the actual file locations, though I seem to remember that they tend to be download and install instead of download and save or install which would make my second idea moot.