limneos

my bad...the diskpart command will work on Vista only.

if you don't have a Vista PC , you can boot any PC with the VISTA installation DVD, (dont' worry this wont' install vista on their disk) and at the first screen select your language etc, press next, then go to repair your pc.
There, it will search for windows installations and won't find any. (IF IT ASKS YOU TO REPAIR AND RESTART SELECT NO!!!) Press next and you will get a screen with several options, one of them is command prompt.
Do the stuff needed there to prepare your USB, then copy the Vista DVD on it. (IN THE WAY DESCRIBED on the link I provided above)