I'm not having any luck figuring out how to upgrade from Home to Pro with an existing key. My system has been running Home and is currently running version 1511. I've decided to go ahead and use an existing key to upgrade to Pro. I did a clean install, expecting to be asked to specify a version and provide a key during install, but was never asked for either. The installer simply formatted the hard drive and installed Home and activated it, with no input from me after the install started other than agree to the terms and tell it my language.
OK, no problem I thought, I'll just go to the Activation setting and give it the new key from there. However, if I tell it I want to change the key it comes back and says the key I'm giving it can only activate Pro and I'm running Home. If I go the Store route and tell it I already have a Pro key, it gives me the same message - it tells me my key is for Pro but I'm running Home. Nowhere along the way does it offer to take my key and give me the upgrade, rather it implies that I must somehow magically upgrade it myself before changing the key. And that would be fine if I could figure out how to do that.
Anyone know how to force an install of Pro when the installer automatically installs Home with no option given to change it?