that I knew...Yes, I was just curious if a computer could have Home and Pro activations stored at the same time
That I did not... But good to knowif the Pro generic key would upgrade the Home version
Either way the PC, First, needed the digital entitlement for windows 10 pro
I was trying to do this, and used the listed method in a different order. I used the generic key in the Change Product Key window, and it upgraded my computer to Windows 10 Pro, even though I have never had a Pro version of any Windows OS on this PC. After the computer restarted it told me that Windows was not activated. I was then able to use my Windows 7 key to activate it. So, it is certainly possible without having the entitlement before hand.
As a test I just went from activated 1511 version of Pro to Enterprise (using generic key NPPR9-FWDCX-D2C8J-H872K-2YT43). It wasn't activated after of course but worked fine.
Putting in either the Home generic key (where I don't have digital entitlement) or Pro (where I do) failed with 0xc004f014 so it seems to be a one way trip to enterprise. Had to restore back. In the old pre-RTM previews you could switch versions at will.
Yeah, activation isn't checked until the upgrade to the new edition is finished and the PC reboots. The first check just verifies the key is a valid key for that edition. It's also a one way trip, can go up, but not down. Windows 8 is the same way. You can go from Core to Pro but not back. Then add Media Center to Pro. A few got caught out with e-bay MC keys that wouldn't activate. Then had to reinstall to go back to Pro and get legal again.
Just did a clean install on my wife's laptop. I used a stock unmodified ISO as a test. I started the install, went to custom and deleted all the partitions so there was no trace of a previous OS. Quit the install and started over from scratch with a blank hard drive. I was not asked to chose Home or Pro and not asked to enter a key. 10 Home was installed by default and activated. Checking activation it states it activated with a digital entitlement. This PC was running 10 Pro with a digital entitlement before I wiped the drive. It looks like it read and used the Windows 8.0 Core OEM embedded key. 10 Home was never installed or activated on this laptop. Just a heads up for those doing a clean install on a blank hard drive. showkey shows the installed key as the 10 Home generic key. And lists the 8.0 OEM key. I just entered the generic Pro key and its upgrading. I'll post back when done and I check activation again.
EDIT: Upgraded and activated without issue. Activation shows activated with a Digital Entitlement. Settings > Update & Security > Activation
So it is not an one step installation to Pro, you have to go to Home first (if both versions are registered on the same computer), but at least it works and it is free. Good to know.
Adding a PID.txt file to the sources folder with the generic 10 Pro key will install Pro by default and bypass any OEM key detection. I've been doing it in Windows 8, 8.1 and 10. If I don't Windows 8.1 Core gets installed on my laptop and I have to then upgrade to Pro. In Windows 8.1 the PID.txt file had my MSDN 8.1 Pro key in it. My laptop has an 8.0 Core OEM embedded key in the BIOS. My MSDN ISO's will detect it and use it automatically unless I add a PID.txt file.
Or you can use ei.cfg :) Windows Setup Edition Configuration and Product ID Files (EI.cfg and PID.txt)
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