I have windows 7 installed and want to go back to windows vista that is on my labtop. I didn't make any recovery disks so I downloaded yours. When I went to put in yours it asked me for a serial number. I don't have a serial number since this is a oem. I tried to use f11 but couldn't reinstall vista so I need a recovery disks since I didn't make one when I had vista installed. Any ideas what to do so I can recover my hp labtop and get it back to vista. Thanks in advance.