The jailbreaking process for Windows RT 8.1 involves several steps:
Boot from the USB again. This exploit unlocks the UEFI, allowing you to boot unsigned operating systems or stay in Windows with unsigned code execution enabled. Critical Limitations Jailbreak for Windows RT jailbreak windows rt 8.1 surface
Charge the battery to at least 50%. Connect your Type Cover or USB keyboard. Boot into Windows RT 8.1. If you are doing a factory reset, ensure you have passed the initial setup (you must connect to Wi-Fi and log in with a Microsoft account—yes, this still works). The jailbreaking process for Windows RT 8