I guess for many guys who pursue the performance and have tried Windows 8/8.1 or even the latest Windows 10, they found they like Windows 7 better, or even want to change back to Window 7. For AppNee, I have a performance list for Windows Pro Editions, that's: 98 > XP > 8.1 > 7 > 8 > 10 > Vista.
After Windows is reinstalled, your old OEM (Original Equipment Manufacturer) information will be lost, so what is a good way to change back quickly? Or if you are not satisfied with the monotonous logo in your system properties. In these cases, you can try OEM-DIY, it makes the system information modifications easier.