I purchased this disk (Windows 7 Professional 64 Bit) to get me out of a hole I did a upgrade from win 7 pro to win 8.1 pro but did not like it but could not get back to win 7 my fault I did not make a boot-up disk with drivers and installation files. I am very impressed with the speedy delivery from Techee and once I had put the disk in and rebooted in recovery mode it installed albeit without drivers but I had made a system image of win 7 so all I had to do was recover from the system image and my laptop was back to it's original state before doing the upgrade. Windows 8.1 would not let me install from the system image file due to different filing system, so I would advise people to make a boot-up recovery disk has I will do from now on. I would recommend Techee to other people for Operating System Disks as I found this company very reasonably priced and the delivery was within 2 days of ordering - A very impressed customer