re-installing

Hi I have a question about re-installing the game and i couldn't really find anything in a quick search.
I'm planning on doing an install of windows vista (i currently have xp) and I'm backing up all my programs.
I'm just wondering about when I re-install GW will I have to download everything again? It's only a problem because I have a download limit and 4GB is nearly half my limit
I have all games on disc and planning on backing up the GW folder.
Thanks

if you just backup your gw.dat you should be fine that's were gw stores all the data.

If you back up your GW folder, that's about all you need. After installing Vista, just copy the GW folder back to Program Files (if necessary) and run gw.exe and GW will "reinstall" itself into Vista.
Note: in Vista, your templates and screenshots will be in a different place - Documents\Guild Wars. I did the above procedure myself a while back, but I don't specifically recall if Vista then moved my Templates and Screenshots, or if I had to move them myself. But either way, that's all that's required - just run gw.exe and (maybe) copy the Template and Screenshot folders.

you will need to copy the Templates / Screenshots in Vista - depending on your setup and drivers you may see a performance hit with Vista..... if so newer drivers will likely resolve that for you.

thanks for the answers everyone very helpful