Convert Windows Server 2008 R2 from Standard to Enterprise

I've had a few cases recently where SQL VMs that have been around for a while (years) have reached the point of needing more than the 32GB of RAM that Windows Server 2008 R2 Standard allows you to use.  Thankfully, there's a nice and simple method for converting your Standard edition server to Enterprise edition using DISM and the generic KMS key with minimal down time that's been documented here on a TechNet blog.  The KMS key is only used for the conversion command, you will still need to re-enter your organizations license key in order to re-activate the OS once the conversion process completes.

1. Open up and elevated PowerShell prompt.
2. Type: DISM /online /Set-Edition:ServerEnterprise /ProductKey:489J6-VHDMP-X63PK-3K798-CPX3Y
3. Wait for the process to complete, and agree to reboot the server.
4. After the reboot completes, login to the server and you'll be asked to complete the activation process.
5. Reboot one more time.  Probably not required, but it makes me feel better.

I've now completed the procedure on several servers with almost no issues.  The one time I did have an issue, the activation of my organizations normal MAK key looks like it didn't process completely, despite the OS reporting a successful activation.  The symptoms of the issue were RDP not working, RDP options not even being present in the Remote Settings tab of the System Properties window, and the OS reporting the full amount of RAM visible, but only 4.0GB usable.  The amount of usable RAM being limited to 4.0GB was easily confirmed using Task Manager.  After doing my best not to freak out, and scrambling to find a solution that didn't involve restoring from the previous backup, I was able to locate the solution here, documented by a Spiceworks user.

Open up and elevated command prompt and ensure you're in the "system32" directory.

Clear any KMS key entries by typing: slmgr.vbs -ckms

Clear any product key entries by typing: slmgr.vbs -upk

Input your organizations product key by typing: slmgr.vbs -ipk xxxxx-xxxxx-xxxxx-xxxxx-xxxxx

Invoke the activation process by typing: slmgr.vbs -ato

After activation completes, you'll be asked to reboot.

I'm still not certain why this one instance of converting the OS to Enterprise edition (or the subsequent re-activation process) caused this to happen.  However it only happened once out of the several of these that I have completed.  Thankfully, I found the easy fix. Needless to say, it's always best to make sure you have good backup to restore from.  Just in case.