Windows RT is the locked-down version of Windows 8 for ARM computers, as seen on Microsoft’s Surface RT tablet and a few other Windows RT devices. Unlike the standard version of Windows 8, Windows RT doesn’t allow you to install your own desktop programs.
You’re limited to the included desktop programs written by Microsoft or Modern apps from the Windows Store. However, there are ways to jailbreak your Windows RT device and run unapproved software on the desktop.
These tricks aren’t for the faint of heart. They’re for the geeks out there who have a Surface lying around and want to hack around with it, making it do more than what it was designed to do.