How do I license Windows 7 Pro from Windows 8 Pro downgrade?

I have a client who purchased a new HP All-In-One that came preinstalled with Windows 8.1 Pro (no Win7 downgrade option).
Under the MS licensing terms, she is entitled to exercise the Windows downgrade rights, so she has asked me to install Windows 7 on the AIO for her.

After installing Windows 7 Pro, all of the drivers and standard software she'd use, I now need to activate the Windows 7 pro.
I've read that you can do this by using any Windows 7 Pro product key during the install and then doing the activation by phone and talking to a MS representative and explaining that I'm downgrading.  But it says that I need to have the Windows 8.1 pro COA...

The problem is that the HP AIO has no COA.  There is NO sticker on the computer or any accompanying documentation that displays the product key.

 We are legally entitled to do this...    How do I proceed?
ReeceICT ConsultantAsked:
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web_trackerComputer Service TechnicianCommented:
When the HP computer was sold it must ship with a legal sticker for the windows 8 OS otherwise the company that sold the computer is in violation of the OEM agreement.  But I have heard that windows 8 is some what different as they ebed it in the bios

This website gives you clues how to extract it from the bios.
ReeceICT ConsultantAuthor Commented:
Well this and every other Windows 8/8.1 computer I have used in the past 6 months has not had the sticker (COA).  So it must be embedded in the BIOS.
I will test the software you linked, but the system has already been rebuilt with Windows 7... and to do this, UEFI had to be disabled.  So it may not be very successful in extracting anything.
☠ MASQ ☠Commented:
This is a great question, mainly because Microsoft & the OEMs didn't really look through the implication for Downgrading Rights from a system which has the Product Key encrypted and embedded in the BIOS and no longer on a sticker on the case.  Welcome to OA3.0!!

The downgrade process is otherwise pretty simple, the one part that causes grief now is "phone Microsoft with your Windows 8 Pro activation Key as proof of Downgrade eligibility".

So where is it?
It's in the code in the machine's BIOS!

Where is my CoA sticker?
You don't have one anymore - because you don't need to know the Key

But you ask for it when I need to downgrade - don't you?
Ahhh.... I'm just going to put you on hold while I talk to my supervisor ...

How to read the "hidden" key?

1) "The simple - keeps Microsoft happy - but not really reading the BIOS trick"
OEMs still put a Win 8 product Key in the registry - it's a "legacy thing" - it's not your actualy activation Key from your BIOS (it's a generic OEM key tied to your manufacturer) but it will show Microsoft you have an OEM Windows 8 system and identifies the manufacturer to them.  You can get it from any one of the numerous Key Finder utilities.  I happen to like Nirsoft's offering ProduKey but Google will find you several good free utilities.

Upside - the Key is unencrypted
Downside - Not the unique code from your systemboard - Requires the Win8 install to be intact so if you've already downgraded you have to put everything back again just to get this info :(

2) The tricky "Read the BIOS" and find your Key trick

You'd think that because people are going to need their Key to downgrade, Microsoft and the board manufacturer's would have made it easy to extract your unique key to prove your downgrade rights to Windows 7?


There are at least two tools available that will read the Key from the BIOS but neither will completely decrypt it.

These are

Microsoft's OA3Tool - included as part of the Windows 8.1 ADK

RWEverything - a neat free (donations appreciated) little utility that lets you poke around your systems hardware addresses

Be aware that both these tools can write directly to hardware as well as read the contents.  If you overwrite your OA3 key then your systemboard will no longer activate Windows 8.

The correct syntax for use of the use of the OA3Tool is:

>>oa3tool.exe /validate

Here is an example output:
OEM Activation Tool 3.0

(c) Copyright 2011 Microsoft Corp.

Version: 6.2.9200

The ACPI MSDM table:
4d 53 44 4d 55 00 00 00 03 e8 41 43 52 53 59 53
  41 43 52 50 52 44 43 54 01 00 00 00 31 30 32 35
  00 00 04 00 01 00 00 00 00 00 00 00 01 00 00 00
  00 00 00 00 1d 00 00 00 42 48 33 52 4e 2d 42 37
  46 44 4d 2d 43 37 57 47 54 2d 34 43 52 34 58 2d
  36 43 4b 48 4d

The ACPI MSDM data :
  Signature:          MSDM
  Length:            85 (0x55)
  Revision:          3
  CheckSum:          0xe8
  OEMID:              ACRSYS
  OEMTableID:        ACRPRDCT
  OEMRevision:        0x1
  CreatorID:          1025
  CreatorRev:        262144

The ACPI MSDM table in hex:
  01 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00
  1d 00 00 00 42 48 33 52 4e 2d 42 37 46 44 4d 2d
  43 37 57 47 54 2d 34 43 52 34 58 2d 36 43 4b 48
  4d  **

ACPI MSDM table payload:
  Version:            1
  Type:                1
  DataLength:          29
  Partial Product Key: 6CKHM

**This is not a real extract so don't try activating from it!!

Open in new window

To convert the MSDM Key into something you can recognise convert the last 29 pairs from Hex to ASCII which should give you five blocks of five characters separated by 4 hyphens (2D in Hex) -   i.e. XXXXX-XXXXX-XXXXX-XXXXX-XXXXX

It's really that simple :)

Upside - you get your actual unique activation key
Downside - Life really is too short!

Good luck - let us know how you get on!

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ReeceICT ConsultantAuthor Commented:
Great explanation Masq.  I'll give that utility a whirl and revisit my hex to ascii conversion.
You should write an article about this so it's easier for people to find in a Google search.
☠ MASQ ☠Commented:
Let's check it works for both of us first :) !!
ReeceICT ConsultantAuthor Commented:
I used the Microsoft OA3Tool to perform the SLIC extraction from the computer in question, but when I try to use that Key to download 8 or 8.1 ISO's it fails verification... So maybe it didn't work.

I'm going to try the same procedure on a HP laptop I installed yesterday that came with Win7pro pre-installed and has 8 pro recovery media.
There was no COA label anywhere with this system so I can only assume the SLIC is in the BIOS again and the recovery media would use a HP product key that is built into their OS image/installer as a blanket product key.

I'll let you know if I get the key from the BIOS and it works on a "test" Windows 8 pro install.
☠ MASQ ☠Commented:
Thanks for the update - the extracted key isn't designed to work for manual activation of Win8 but it is the evidence you need for Microsoft to give you a one-time activation key for the Win 7 downgrade.
☠ MASQ ☠Commented:
ReeceICT ConsultantAuthor Commented:
Despite the very frustrating conversation with microsoft to obtain a Windows 7 Professional product key for software activation, this was the exact answer I was looking for.

Thanks again.

Nice article BTW.
ReeceICT ConsultantAuthor Commented:
Can I just provide an update on this for you.  You may wish to amend your article explaining the procedure:

Once you have the Windows 8/8.1 Pro SLIC (whether it's the OEM one from Toshiba/HP etc. extracted from the registry or the unique product key extracted from the UEFI BIOS) keep a record of this for proof of authenticity and eligibility for the Windows OEM Downgrade rights (

Then you can install Windows 7 Pro (from an OEM DVD or USB flash drive) and use the Windows 7 Product Key that corresponds to the installer you are using to input during the installation.

Once Windows is installed, you need to perform the software activation manually by calling the Activation Center, proceeding with the usual activation steps and press the appropriate button that will connect you to a licensing technician.
Explain that you are exercising your downgrade rights and provide them with the authentic Windows 7 Pro product key.  TIP: You can use the same Windows 7 Pro product key in this procedure over and over as many times as you require provided the product key isn't "blocked".
Once they validate that it is a genuine key, and you read the 9 blocks of 6 numbers, they will provide you with the corresponding activation string.

Once the activation is complete, you can breathe a sigh of relief that the software is activated according to the Microsoft Software License Terms and will be compliant with any software licensing audits performed provided you keep evidence of the original Windows 8/8.1 pro product key (or even a copy of the computer's invoice that specifies it has Windows 8/8.1 pro pre-installed).

Microsoft WILL NOT provide a downgrade product key or a Windows 7 pro product key.  They will activate an existing Windows 7 Pro product key as part of fulfilling the OEM downgrade rights obligation.    As I mentioned earlier - ANY Windows 7 Pro license key will be suitable as long as it matches the installer used (ie. OEM DVD = OEM Key, Retail DVD = Retail Key, Volume License = Volume License Key).
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