By Ryan Stevens.
Some Windows 8 PCs come with what are called “downgrade rights.” If your PC comes with Windows 8 Pro, you can downgrade to Windows 7 Pro just by installing it on top of your existing OS. You’ll need a legitimate disc and product key, but you can just use an old or used one—after you install, you can call Microsoft and they’ll activate your downgrade for you. You can even downgrade multiple machines with the same CD and key.
Not all computers come with downgrade rights , so be sure to do a bit of research before you try this out or buy your new Windows 8 computer. It can be a bit of a hassle, but it’s a nice option if you really want to keep using Windows 7.