I found an interesting trick. I have access to Windows 8 Pro-licensed laptops where they have *never* had Win8 loaded on them; they come with Windows 7. So the burned-in OA3.0 key has never been used. With Win8 this is not a problem, on install it sees the key, activates, all good. As we have seen with Win8.1, it sometimes can't read this key. So we use RWeverything etc. to get the key, punch it in manually, and it takes it and activates. (you knew that, right?) It dawned on me that Win8.1 is effectively saying "I can't read the firmware key, but you seem to know it so I'll take your word for it." So what is to stop one from using the firmware-read key.. on a totally different machine? Curious, I tried it. I used a firmware-burned key, which will *never* be used on the computer it's on, to activate on a non-OEM computer. It "worked." I use quotes because while it says it's activated, and nothing in slmgr /dlv leads me to believe it will blow up (licensed, rearm count 1000 etc.), Event Viewer has one odd warning entry every few minutes: "Installation of the Proof of Purchase from the ACPI table failed. Error code: 0xC004F057" I'm wondering if there's some timer where it will actually start to *care* about this, and how to avoid any potential de-activation. Googling, this error code is fatal on Win7, and seems to appear out of nowhere when the OEM info gets borked. It makes the OS non-genuine and creates headaches. So far I'm on day 11 of the install and it seems fine. The only real Hail Mary I have is to try upgrading to WMC with my WMC upgrade key, but since I already used it with the old Win8 trick activation from last year, I am worried it will throw it into a deactivated state if it thinks I used the key on two different Windows installs (which is true though they are the same hardware). Thoughts? Is this error worth caring about? Event Viewer entries I don't care about. Black backgrounds and dialogue boxes I care about.