Hey guys, I've got a new Spectre x360 which came with Windows 10 Home installed. I thought, no big deal, by now I'm an old hand at upgrading to Pro. But this one has me stumped, as the normal methods don't seem to be working. Here's what I have done: 1. Completely clean/reformat the harddrive and install Windows 8.1 2. Activate Windows 8.1 with MSTK (confirm activation) 3. Install all drivers, including (W)LAN (I used Snappy Driver, it found everything except some Intel Sensor thing and another unknown device), download and install updates. 4. Create an ISO of Windows 1511, with pid.txt added to Sources so it will upgrade to Pro. 5. Mount ISO, begin upgrade to Pro 6. Windows 10 Pro installs.... But it is not activated. I get this error: Activation failed because this device doesn't have a valid digital entitlement or product key. Error code: 0x803F7001 I double and triple checked that Windows 8.1 said it was activated, and I was under the impression I did more than needed on the drivers front, as only the (W)LAN driver is supposed to be essential. I'm completely stumped. I've used this exact method on other computers with great success, including the one I'm currently typing on (which is also a Spectre x360) so I have no idea why this one is being so stubborn. Can anyone offer advice on where I may have gone wrong and/or what else I could try? Thanks!