Porting SLIC 2.1 from the Host to the VM to allow Downgrade Rights OEM SLP

One of the biggest difficulties with regards to the use of Virtual Machines is obtaining the Windows license required to activate the Virtual Machine.

Windows 7, Windows Vista and Windows XP have all Reached End of Retail and OEM sales so a new license cannot be purchased from Microsoft.

If you have bought a major OEM machine with a Windows 8.1 Pro OEM License or Windows 10 Pro OEM License your system has a SLIC version of 2.1 and this may be used as an activation mechanism for Downgrade Rights to Windows 7 Pro (or Windows Vista Business). These legacy OS will however lack the drivers for the new hardware and it will be impossible to install the OS and get it to run reliably in most cases (meaning downgrade rights by directly installing on the hardware is theoretical and of no practical use). This can be resolved by virtualising the Windows Installation with VMware and porting your OEM SLIC 2.1 from the host to the guest (which isn’t done by default).

Checking if your Host PC has a SLIC Version of 2.1

Fortunately systems which ship with the Pro Edition of Windows i.e. Windows 10 Pro OEM and Windows 8.1 Pro OEM have a System Licensed Internal Code SLIC version of 2.1.

win10Pro Win8Pro

A SLIC version of 2.1 is required for Windows 7 Pro OEM SLP (and will also work with Windows Vista OEM SLP).

To determine your SLIC install RW-Everything, launch RW-Everything and select Access → ACPI Tables:


Select the SLIC Tab:


Scroll down until you get the SLIC Marker Structure. You are interested in 2 fields:

  • OEM ID
  • SLIC Version

In this case the OEM is Dell and the SLIC Version is 2.1.

Downloading and Installing VMware Player

Download and install VMware player.

Setting up your Virtual Machine

Select File → New Virtual Machine:

Select Remind me Later when VMware tells you about updates:

Select I will install this Operating System later and Next.

If you do not select this option the VMware setup will ask you to input a Windows Retail Product key and break the OEM SLP present on your Reinstallation DVD/.iso. OEM SLP in any case won’t work until we pass through the SLIC to the VM.

Select Microsoft Windows and select your Version the press Next. I will use Windows 7 (this guide works equally well on Windows Vista) as an example:

Name your VM and then select Next:

Select Next:

Select Customise Hardware:

Select New CD/DVD and then select Browse:

Select your Dell Windows Reinstallation .iso and then select open. In this case I will use the Dell Windows 7 64 Bit Pro Skylake April 2017 .iso:

Select Finish:

Right click your VM and select Settings:

Select Options:

Highlight the working directory and copy it:

Paste it in Windows Explorer:

Right click the VMware virtual machine configuration and select open with… notepad:

Add the following to the end of the VMware virtual machine configuration file and save.

acpi.passthru.slic = “TRUE"
acpi.passthru.slicvendor = “TRUE"
SMBIOS.reflecthost = “TRUE"

Reference to this Dave Parsons here.

Note simply copying the three lines from this website into notepad may subtly change “ and " into ” and “. This is not observable in notepad but results in VMware not recognising the setting in the VMX file… This is more obvious when the text is pasted from Notepad into Microsoft Word as shown below. To ensure this doesn’t happen copy and paste the “ and " from a line above (e.g. copy and replace all those I’ve marked in red by an existing line an example which I’ve marked in green).

Then select file save and close down notepad.

You can now launch your VM and follow through with the Clean Windows Installation.

Installing Windows 7 on the Virtual machine

I will not go through this here just now.

Checking your OEM SLIC 2.1 has been ported to your VM

This can once again be done with RWEverything:

Now if I right click Computer and select Properties:

I can see Windows 7 Professional is activated on the VM running on my host Latitude 7350 using the host Latitude’s SLIC Version 2.1:



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