Wipe windows 10 info from bios or cmos

3

I've read that windows 10 writes it's registration/configuration information into the bios (or was it cmos...) of your motherboard to close the loop of using the same product key as both a dual boot system and a virtual box installation.

I originally installed windows 10 from the upgrade offer and used it as a dual boot (not a virtual box). I gave it a shot for a few months, but by the time I decided it wasn't really good enough to be my full time OS I couldn't revert back to windows 7. These days, the computer I tested it out on only runs arch linux. I got rid of the dual boot, formatted over my windows partitions, and haven't looked back. Well, maybe a few glances, every once and a while I need windows again to run software that is for windows only and making arrangements for this is getting inconvenient.

Since I have a valid windows 10 product key I'm thinking of setting it up as a virtual box, but I know there will be problems with the registration because that computer already has this product key of windows 10 embedded into it somehow.

What do I need to do to my bios or cmos to wipe out this information so I can start clean?

Additional information:

This is not a laptop or desktop purchased from a store with an OEM license affixed as a sticker to it.

My motherboard is a asus P8Z77-V

From the Under Additional Terms / License Rights and Multi User Scenarios in the answer: https://superuser.com/a/546688/409815 I can see that you can only use one copy of your product number for a stand alone system or a virtual system, but not both.

This isn't my original resource for determining that windows 10 wrote product key information to the bios, but at least there are multiple confirmations that this process is a current practice: https://superuser.com/a/1096027/409815

There's a lot of conflicting information about this one out there so I won't reference this one: There's dispute about whether problems can arise from returning to windows 7 from windows 10 outside of the 1 month grace period following a free upgrade to windows 10.

Conclusions I have drawn about my system:

  • Having installed windows 10 on my computer (once as an upgrade, and a second time with my new windows 10 product key from the upgrade as a clean install) I am quite sure that my bios now contains some sort of registration.
  • I won't have any problems reinstalling a standalone version of windows 10 to my computer because the hardware configurations are the same and it will agree with the information stored in the bios.
  • I expect to have problems, or at the very least trigger some flags with MS if I try to install windows 10 in a virtual box on a computer that already has registration info in it's bios.
  • Maybe if I had found some way to properly uninstall this wouldn't be an issue, but I just formatted over the install while playing with my partition table one day.

EngBIRD

Posted 2016-11-04T22:13:43.637

Reputation: 148

2Your Windows 10 key is NOT embedded in your hardware, your computer, is not incapable of storing a Windows key. You have misinterpreted what your read – Ramhound – 2016-11-04T22:30:28.133

1Large OEM manufacturers started putting the windows license in to their hardware (the ACPI tables) starting with computers that came with Windows 8. No OS can write to the ACPI tables or erase from it. It is in a read only chip that is manufactured to have that data in it. It is either a ROM chip or the EE pins in the EEPROM are not connected to anything, except possibly some JTAG pads. You are not expected to remove that info in any way. – BeowulfNode42 – 2016-11-05T00:48:02.700

Non-large-OEM Windows 10 reads info from your bios like make/model/serial and tells MS servers that info over the net, that is how W10 becomes linked to your BIOS. You can use your MS account that the computer is registered to, to tell MS that copy of windows has been removed to make a retail license available for use on other hardware. – BeowulfNode42 – 2016-11-05T00:50:08.627

@BeowulfNode42 My computer is not linked to a MS account, in fact that's one of the reasons I ditched it for arch linux in the first place. It took a while to even get a guest account setup without a MS account. In their desperation to collect personal information they didn't stop to think that a guest account would be used by many people and therefore one MS ID wouldn't make sense. I don't anticipate hardware/bios linked ID's to be a problem because I haven't changed any of my hardware recently. – EngBIRD – 2016-11-05T00:55:00.910

Note that a VM is considered a different computer and needs the license to be transferred. Also note that W10 home is not licensed to be used in a VM. Also see a page like http://www.groovypost.com/howto/transfer-windows-10-license-new-pc/ that shows you how to go through the transfer without an MS account.

– BeowulfNode42 – 2016-11-05T01:17:54.517

@BeowulfNode42 Thanks, I don't think I have home, I think the upgrade gave me W10 professional, but between the sketchy privacy settings in W10 and extra work transferring accounts, I see nothing but reason after reason to go back to Windows 7 for the few programs I'm stuck with MS for. – EngBIRD – 2016-11-05T04:26:36.007

Answers

2

What do I need to do to my bios or cmos to wipe out this information so I can start clean?

You don't have to do anything

The hardware you have is incapable of storing a Windows key within the ACPI table.

Just download a Windows 7 ISO from Microsoft for the same version you have a license key to. I submitted an answer in the past that explains how you download the correct ISO from Microsoft.

Having installed windows 10 on my computer (once as an upgrade, and a second time with my new windows 10 product key from the upgrade as a clean install) I am quite sure that my bios now contains some sort of registration.

BIOS does not have the capability to store a Windows license key. UEFI does not have the capability to either. Your motherboard has UEFI not BIOS. Your motherboard has a blank ACPI table. Any motherboard you purchase, from a store like Newegg or Amazon, has a blank ACPI table.

I won't have any problems reinstalling a standalone version of windows 10 to my computer because the hardware configurations are the same and it will agree with the information stored in the bios

You won't have problems installing Windows 7 on your machine again.

I expect to have problems, or at the very least trigger some flags with MS if I try to install windows 10 in a virtual box on a computer that already has registration info in it's bios.

Your registration information is not stored in your motherboard's BIOS, which does not exist, because your motherboard has UEFI not BIOS. Your registration information also isn't stored in the ACPI table, for the reason I already explained, because you have a retail license.

There's a lot of conflicting information about this one out there so I won't reference this one: There's dispute about whether problems can arise from returning to windows 7 from windows 10 outside of the 1 month grace period following a free upgrade to windows 10.

Only uninformed people about the actual Windows 10 license and the free upgrade offer dispute the fact you can reinstall your Windows 7 license.

From the Under Additional Terms / License Rights and Multi User Scenarios in the answer: https://superuser.com/a/546688/409815 I can see that you can only use one copy of your product number for a stand alone system or a virtual system, but not both.

Having experience in this matter. You can either run your Windows 7 license or your Windows 10 license, you use do both, depending on the virtualization software used your virtual machine will appear to be your physical machine.

Ramhound

Posted 2016-11-04T22:13:43.637

Reputation: 28 517

Only devices that came with Windows 8, Windows 8.1, or Windows 10 have the capability to store the license key in the ACPI table. Your computer, since it came with Windows 7, has a shiny COA sticker with license key printed on it. That's the only copy of the license key so hopefully the sticker is still around – Ramhound – 2016-11-04T22:39:56.727

Thank you for your answer, but I think you misunderstood my question. My computer is not a laptop and didn't come with windows 7. I installed it, and later invalidated that separately obtained product key by using the windows 10 free upgrade. The motherboard in question is a asus P8Z77-V. The OS in question that I am concerned about the BIOS is windows 10. Your answer indicates that I indeed have a license stored in this "ACPI" table because my question is specific to what Windows 10 has written. – EngBIRD – 2016-11-04T23:04:31.657

You cannot invalidate a Windows license. You never specified what version of Windows came with your computer. When you clarify your question I will clarify my answer. If you upgraded your installation to Windows 10, and it didn't come with windows 7, there is only one possible version eligible for the upgrade. Your question isn't clear enough so I am unable to answer your actual question – Ramhound – 2016-11-04T23:12:04.773

No version of windows came with my computer. I obtained the desktop hardware to my own specifications and ran linux off it for years. Then I needed to do some windows work and through my institution obtained a windows 7 product key. When I used the windows 10 upgrade, the literature clearly said my current windows 7 product key was no longer valid. I will add this and some more info (and any supporting references I can find) to my question. Thanks for your attention to my problem. – EngBIRD – 2016-11-04T23:15:47.337

You can still use your Windows 7 license since your no longer using the Windows 10 license. Your Windows 10 license still isn't stored in your hardware and your hardware still isn't capable of storing the license in its ACPI table (intact the table itself is blank). Technically your Windows 10 license, upgraded from a non-OEM Windows 7 license, can be moved to a virtual machine but only if that's the only installation you use (you can have both) – Ramhound – 2016-11-04T23:16:53.160

Thats been reported by "tech writers" who know nothing about Microsoft's actual licensing terms. – Ramhound – 2016-11-04T23:53:29.697

Thanks, that's really good news. Under what circumstances is the information written to the ACPI table? My mother board (the asus p8Z77-V) is a ~2012 model which indeed predates windows 10, but possibly not the concept, as I would assume that the ACPI table would have had to exist with considerable prevalence of hardware for MS to consider implementing it. – EngBIRD – 2016-11-04T23:57:17.790

Under no circumstances; Only an OEM has the hardware required to write to the ACPI table. While your motherboard has a ACPI table it's. Lank, and it does not support the revision of the standard, that supports storing the license key. Again, your Windows 10 key, is not stored with the ACPI table on your motherboard. – Ramhound – 2016-11-04T23:59:31.000