reformat and reinstall vista

Hi there,

Initially my computer came with windows vista, then i renistalled windows 7 on it and was on my company's domain. Now i need to reformat my computer and reinstall windows vista on it. I don't the installation cd for vista and any ISO image i have downloaded doesnt seem to work. As my laptop doesn't boot up with that CD. I have a compaq presario CQ60.

Please help !!!!!


Thanks in advance