Installing Vista on an external hard drive

ok so here is my situation. I curently am using a Macbook Pro with 100 gig hard drive. I am running out of room due to the ammount of music, videos, and pictures i have on my computer. The question i am having is my windows vista virtual hard drive is takeing up 25 gigs of space. Is there any way i can move that virtual hard drive to an external hard drive that is running usb 2.0 so i can free up space on my internal hard drive? Any help would be greatly appreciated
edit - i am also running parallels desktop 3.0

 

I was able to run it on both usb 2.0 and firewire. Although it ran painfully slow on a usb drive. You could alwasy make a copy and try it...

 

I run some of mine off of my firewire 800. That is much much faster than USB. Good luck.

 

how do i get it setup on a external hdd it dosent seem to be giving me an option anywhere

 

Its a little tricky. I installed mine ON the Mac then copied it to the Firewire, expanded the fixed size there, and redirected the config files to point to it. Sorry that's not very detailed, but it works... or did until I upgraded to 3.0... LOL