We have a VM which is running Windows Server 2008 R2 Standard with 32GB RAM. Recently we have to add more RAM to it to improve SQL Server performance. Another 32GB RAM is added through VM configuration. But since it is a Windows Server 2008 R2 standard edition which has a limitation of only being able to use 32GB RAM MAX, it still can’t see the full 64GB. Found out we have to upgrade the edition to Enterprise in order to fully utilize 64GB RAM. By following this blog post for upgrading Windows Server 2008 R2 without media, I ran the script to initiate the upgrade:

DISM /online /Set-Edition:ServerEnterprise /ProductKey:XXXXX-XXXXX-XXXXX-XXXXX-XXXXX

I used the right MAK license key for Windows Server 2008 R2 Enterprise. But the upgrade was failed. The error message is something like this:

Error: 1605

The specified product key is not valid for the target edition.
Run this command again with a product key specific to the target edition.

The DISM log file can be found at C:\Windows\Logs\DISM\dism.log

For example if upgrading to Enterprise and using a MAK key, the DISM log would contain the following entry.

dism /online /Set-Edition:ServerEnterprise /ProductKey:[abcde-abcde-abcde-abcde-abcde]

Error DISM DISM Transmog Provider: PID=5728 Product key is keyed to [], but user requested transmog to [ServerEnterprise] - CTransmogManager::ValidateTransmogrify
>
> CTransmogManager::ValidateTransmogrify
>
> Error DISM DISM Transmog Provider: PID=3880 [Upgrading system]: The specified product key is not valid for the target edition.
>
> Run this command again with a product key specific to the target edition.
>
> [hrError=0x80070645] - CTransmogManager::EventError
>
> Warning DISM DISM Transmog Provider: PID=3880 The selected OS cannot upgrade to [ServerEnterprise] - CTransmogManager::TransmogrifyWorker
>
> Error DISM DISM Transmog Provider: PID=3880 Failed to Upgrade! - CTransmogManager::TransmogrifyWorker(hr:0x80070645)
>
> Error DISM DISM Transmog Provider: PID=3880 Failed to upgrade! - CTransmogManager::ExecuteCmdLine(hr:0x80070645)
>
>

I Bingo a little bit about this error message. Found a KB which is exactly for it. Looks like I can’t use our MAK key to do it since the key works for multiple editions. DISM doesn’t know what to do with it. I have to get a KMS Client Setup Key for Windows Server 2008 R2 Enterprise to do the upgrade first. So I get the KMS key from here which is 489J6-VHDMP-X63PK-3K798-CPX3Y.

Then I ran the upgrade script again. It worked this time. After the upgrade and reboot, I have to use these two script to change the product key to my correct MAK key, and activate windows. Otherwise, windows will show it is not a genuine windows installation.

cscript.exe %windir%\system32\slmgr.vbs /IPK XXXXX-XXXXX-XXXXX-XXXXX-XXXXX

cscript.exe %windir%\system32\slmgr.vbs /ato

After all these were done, my VM is able to see and use full 64GB RAM right now. Cheers!