I understand this is possible with ubuntu installed first but I have windows 7 already installed. Is this possible?

My boyfriend just got a new computer with Windows 7. I am still (sadly) running vista and I would really like to have 7. Is it possible for me to wipe my computer clean (after a back up, of course) and use his discs to get the Windows 7 OS? or am I going to run into registration issues?

I already made a second Partition and am able to install a second copy but I’m curious, Is it possible to dual boot windows 7, and XP Home edition? Or it just Windows 7 and XP Professional?

i have pc with windows ME and i want to install windows xp on it. anyway, i don’t have the start up disk. is it possible to install windows xp over windows ME without using start up disk?