There has always been some sort of confusion regarding OEM Downgrade Rights because Dell and Microsoft are separate companies and although their business models are linked there are some substantial differences.
Activation Mechanisms – System Locked Preinstallation and Digital Entitlement
Windows XP OEM License – SLIC 1.0
For Windows XP there was a System License Internal Code (SLIC) of Version 1 embedded in the Legacy Dell BIOS. A Dell Windows XP factory image or Reinstallation CD could install a generic system locked preinstallation key and would activate offline if the correct SLIC was present in the Legacy BIOS.
Windows Vista OEM License – SLIC 2.0
For Windows Vista there was a System License Internal Code (SLIC) of Version 2.0 embedded in the Legacy Dell BIOS. A Dell Windows Vista factory image or Reinstallation DVD could install a generic system locked preinstallation key and would activate offline if the correct SLIC was present in the Legacy BIOS.
The SLIC Version can be checked by use of RW-Everything Portable and selecting → Access → ACPI Tables → SLIC, then scrolling down:
There was also downgrade rights from Windows Vista Business to Windows XP Pro via Downgrade Rights. The SLIC 2.0 would also work with Windows XP Reinstallation CDs.
Systems models released ~6 months-1 year before the release of Windows 7 had a free upgrade to Windows 7. To facilitate this free upgrade Dell released a BIOS Update which updated the SLIC from Version 2.0 to Version 2.1 for that model. See below.
Windows 7 OEM License – SLIC 2.1
For Windows 7 there was a System License Internal Code (SLIC) of Version 2.1 embedded in the Legacy Dell BIOS. A Dell Windows 7 factory image or Reinstallation DVD could install a generic system locked preinstallation key and would activate offline if the correct SLIC was present in the Legacy BIOS.
The SLIC Version can be checked by use of RW-Everything Portable and selecting → Access → ACPI Tables → SLIC, then scrolling down:
There was also downgrade rights from Windows 7 Pro to Windows XP Pro via Downgrade Rights. The SLIC 2.1 would also work with Windows XP Reinstallation CD.
There was also downgrade rights from Windows 7 Pro to Windows Vista Business via Downgrade Rights. The SLIC 2.1 would also work with Windows Vista Reinstallation DVD. In practice the popular versions of Windows were Windows 7 and Windows XP, Windows Vista was not popular so very few systems were downgraded to Windows Vista.
Windows 8.0, 8.1 and 10 OEM License – MSDM 1, 2, 3
At the time of release, the Unified Extensive Firmware Interface (UEFI BIOS) was released. With the UEFI BIOS the Microsoft Digital Marker (MSDM) was released which contained a unique 25 digit product key. A Windows 8.0 Factory Image or Windows 8.0 Installation Media of the correct Edition would input this during installation.
The SLIC Version can be checked by use of RW-Everything Portable and selecting → Access → ACPI Tables → MSDM:
Systems with a Windows 8.0 Pro OEM License would have a SLIC Version of 2.1. This allowed one to perform downgrade rights to Windows 7 Pro OEM. A Dell Windows 7 Pro factory image or Reinstallation DVD could install a generic system locked preinstallation key and would activate offline if the correct SLIC was present in the Legacy BIOS.
The SLIC Version can be checked by use of RW-Everything Portable and selecting → Access → ACPI Tables → SLIC, then scrolling down:
The activation mechanisms for Windows 8.1 were identical to Windows 8.0 however Windows 8.0 Installation Media and Windows 8.1 Installation Media without Update 2 were selective and did not accept Windows 8.1 and 8.0 keys respectively.
The activation mechanisms for Windows 10 however the original build of Windows 10 Version 1507 which I classified as an Insider Build did not accept Windows 8.1 and 8.0 keys respectively. Windows 8.1 Installation Media was never updated to accept Windows 10 Product Keys. Microsoft stated there is a supported Downgrade Path from Windows 10 Pro to Windows 8.1 Pro OEM but there is no activation mechanism to facilitate this.
Windows 10 Free Upgrade to Windows 7 OEM Licenses
Windows 10 Version 1511 Installation Media was updated to treat Windows 7, 8.0 and 8.1 Keys as Windows 10 Keys. Thus for Windows 8.0, Windows 8.1 and Windows 10 the MSDM Product Key is input from the UEFI BIOS.
For Windows 7 the Unique Product Key affixed to the systems COA (often found under the battery compartment) can be input during installation:
Inputting this Product Key during installation or performing an in place upgrade from Windows 7 OEM activates Windows 10 using "Digital Entitlement". Essentially your motherboard details are stored with a Microsoft Product Server and you are given the green light for Product Activation. If you ever clean install, you can do so without a Product Key, so long as you install the correct edition, the system will automatically reactivate when online. In the background it will resubmit your motherboard details to the product activation server, which will find a match and reactivate your system.
Installation Media
There have been numerous issues with regards to obtaining installation media for regular OEM Licenses and more so for performing downgrade rights. In many cases, it seemed Microsoft didn't properly think out some policies. It was for this reason I started writing this unofficial Dell Windows Reinstallation Guide and my unofficial workarounds were perhaps carried out millions of times.
I am glad to say that with Windows 10, Microsoft have carried out all my suggestions regarding Windows 10 Installation Media. i.e. to Provide a Single Multi-Edition Windows 10 Installation .iso which covers all Windows 7 OEM, Windows 8.x OEM and Windows 10 OEM Licenses which is downloadable for free without the need for a Product Key from Microsoft.
Windows XP Reinstallation CD/DVD
This installation media is now obsolete and the Operating System has Reached End of Life.
This Operating System had no official download link but all systems were shipped with a Windows XP Installation CD/DVD.
This Operating System has Reached End of Life long ago.
Windows Vista Reinstallation/Installation DVD/.iso
This installation media is now obsolete and the Operating System has Reached End of Life.
All systems were shipped with a Windows Vista Reinstallation DVD.
One could download Retail Windows Vista setup files from Digital River and use ImgBurn to create an installation .iso. The download links were removed when Windows Vista reached End of Life.
Windows 7 Reinstallation/Installation DVD/.iso
Initially all systems shipped with a Windows 7 Professional Reinstallation DVD. Then Microsoft enforced all OEMs to undertake an OEM Media Reduction Policy whereby they would provide a Factory Image Only with instructions to make their own installation media. Of course many users didn't do this and then were stuck when their hard drive failed or OS got corrupted.
Many years after we asked Dell for an official download link for an Up to Date Windows 7 Pro OEM Reinstallation .iso with USB 3.0 Driver and Storage Controller Support for all Hardware Dell Support with Windows 7 Pro, Microsoft allowed them to grant our request:
Download Windows 7 "SP2" Pro OEM Reinstallation .iso (January 2016) from Dell
For other (non-Dell) OEM Licenses Windows 7 .isos were available to download from Digital River. The download links were removed when Microsoft replaced the Digital River Server with their own one. Their website asked for a Retail Only Product Key but could be overiden by using the Unofficial Windows iso Download Tool which generates the Download Links from Microsoft's servers, more details here:
Download Windows 7 SP1 (November 2011) Commercial OEM and Retail .iso from Microsoft
Windows 8.0 Installation DVD/.iso
This installation media is now obsolete.
Again Dell would provide a Factory Image Only with instructions to make their own installation media. Of course many users didn't do this and then were stuck when their hard drive failed or OS got corrupted.
Dell would provide a Windows 8.0 Reinstallation DVD if requested when within warranty however the OEM Editions weren't clearly marked on the model and users quite often got sent Windows 8.0 Home Reinstallation DVDs instead of Windows 8.0 Home Single Language Reinstallation DVDs. Also the optical drive started to become obsolete and DVDs were shipped to some systems without Optical Drives. Finally in most cases the Optical Drive (in systems where it was present) was not listed as a UEFI Boot Device which passed Secure Boot so users had to lower the security of their system in order to install.
Microsoft had a Retail Downloader which required a Windows 8.0 Product Key to use. Unofficially one could download Windows 8.0 with a Windows 8.0 Retail Product Key and then use this Installation Media for Reinstallation of their Windows 8.0 OEM License.
Windows 8.1 Installation DVD/.iso
This installation media is now obsolete.
Again Dell would provide a Factory Image Only with instructions to make their own installation media. Of course many users didn't do this and then were stuck when their hard drive failed or OS got corrupted.
Dell would provide a Windows 8.1 Reinstallation DVD if requested when within warranty however the OEM Editions weren't clearly marked on the model and users quite often got sent Windows 8.1 Home Reinstallation DVDs instead of Windows 8.0 Home Single Language Reinstallation DVDs. Despite Windows 8.1 being a Free Upgrade to Windows 8.0, Windows 8.0 and Windows 8.1 Product Keys were not cross compatible and users again got stuck with the Product Key during installation. Users could install Windows 8.1 using a generic product key, look up their MSDM key and change the key post-installation to activate. Also the optical drive started to become obsolete and DVDs were shipped to some systems without Optical Drives. Finally in most cases the Optical Drive (in systems where it was present) was not listed as a UEFI Boot Device which passed Secure Boot so users had to lower the security of their system in order to install.
Microsoft had a Retail Downloader which required a Windows 8.1 Product Key to use. Despite Windows 8.1 being a Free Upgrade to Windows 8.0, Windows 8.0 and Windows 8.1 Product Keys were not cross compatible and users again got stuck when the Downloader asked for a Product Key. A glitch could be invoked with a Windows 8.0 Retail Key. One could launch the Windows 8.0 Downloader, input the Windows 8.0 Key and close then quickly launch the Windows 8.1 Downloader and this would bypass the Product Key screen. Users could install Windows 8.1 using a generic product key, look up their MSDM key and change the key post-installation to activate their OEM License.
Windows 8.1 with Update 1 Installation DVD/.iso
This installation media is now obsolete.
This had the same issues as Windows 8.1 (No Update) Installation Media however Microsoft patched this Downloader so the glitch with the Windows 8.0 Key couldn't be used.
Windows 8.1 with Update 2 Installation DVD/.iso
Again Dell would provide a Factory Image Only with instructions to make their own installation media.
Microsoft released the Windows 8.1 with Update 2 Media Creation Tool:
Download a Windows 8.1 OEM or Retail .iso.
The Windows 8.1 Media Creation Tool did not ask for a Key to Download the Installation .iso. They released it which offered 5 Editions as separate downloads which covered all the Windows 8.0 OEM and Windows 8.1 OEM Licenses. This installation media would automatically accept and input Windows 8.0 and 8.1 OEM Licenses but only of the correct Editions, the media wouldn't tell you had a key for another Edition. In other words if one got asked for a Product Key during Installation, they had the wrong Edition. Moreover they sequentially released 2 additional OEM "with Bing" Editions on budget hardware and did not Provide Installation Media for these OEM Licenses.
Windows 10 Version 1507 Installation .iso
The Windows 10 Media Creation Tool did not ask for a Key to Download the Installation .iso. They released it which offered 5 Editions as separate downloads which covered all the Windows 10 OEM Licenses. This installation media would automatically accept and input Windows 10 OEM Licenses but only of the correct Editions, the media wouldn't tell you had a key for another Edition. Moreover this installation media only accepted Windows 10 Product Keys Despite Windows 10 Being a Free Upgrade to Windows 10.
The original Windows 10 was a "Free Upgrade" to Windows 7 and Windows 8.0/8.1 which was "Upgrade Only". Unfortunately Microsoft did not follow our advice when we submitted feedback telling them that upgrade installs often go sour and of course users lost their factory image from their older version of Windows when this happened.
Windows 10 Version 1511, 1607, 1703 Installation .iso
The Windows 10 Media Creation Tool did not ask for a Key to Download the Installation .iso. They released it which offered 5 Editions as separate downloads which covered all the Windows 7, 8.0, 8.1 and 10 OEM Licenses. This installation media would automatically accept and input Windows 8.0, 8.1 and 10 OEM Licenses but only of the correct Editions, the media wouldn't tell you had a key for another Edition. In other words if one got asked for a Product Key during Installation, they had the wrong Edition. For a Windows 7 OEM Product License you could manually input the Product Key from the COA.
Windows 10 Version 1709 and Newer Installation .iso
The Windows 10 Media Creation Tool did not ask for a Key to Download the Installation .iso. They released it which a single multi-Edition installation .iso which covered all the Windows 7, 8.0, 8.1,10 OEM Licenses. This installation media is multi-edition and thus would automatically accept and input all Windows 8.0, 8.1 and 10 OEM Licenses. For a Windows 7 OEM Product License you could manually input the Product Key from the COA.
