I upgraded my Surface 3 to Windows 10 a long time ago. I was wondering how to get back to Windows 8.1 now that the windows.old folder is gone. I only see reset as an option in the recovery menu, and that just puts a vanilla version of Windows 10 on it. It has become sluggish lately (probably because of all the updates to Windows 10)/. Is there a place on the web where I can download a Windows 8 or Windows 8.1 image from and put this on the Surface 3 again somehow? If so, where is the key stored for Windows 8.1 on the surface 3? Is it in the BIOS still, even after upgrading to Windows 10? Has anyone successfully done this?