Just after release of Windows 10, you may be one of those technical daredevils who boldly loaded Windows 10 on your Surface Pro 3. But what if your sad soul regret for that decision, don't worry. Not all is lost though. You can bring Windows 8.1 back to your Surface Pro using a USB recovery drive.
BE WARNED! This action will wipe out your Surface Pro 3 and all of the data on its hard drive. Was I clear enough?
Steps to remove Windows 10 Technical Preview from Surface Pro 3:
Hopefully, everything is back to normal now. You can sign in, download all of your apps and move your backed-up data to your newly-restored Surface Pro 3.
Read also: How to install Windows10 Technical Preview
Source: WPCentral