Backing up files onto D drive?

I have an .ISO file of Windows 7 Ultimate and I've been wanting to install it for a while (I currently have Vista) and since I don't have an external hard-drive I was considering backing up all my files on to my D drive and then formatting my C drive and putting 7 on it, would it work?

Yes as long as you install it to c and don't format d

Sweet, will probably try in a few days.