KMS_Error_0xC004C008_Activating_Client

Hello, my name is Scott McArthur. I am a Senior Support Escalation Manager in the Windows group and today’s blog will cover KMS volume Activation.

With Windows Vista we introduced 2 methods for activating volume license versions of Windows. Key Management Service (KMS) and Multiple Activation Key (MAK). KMS keys are grouped to activate different sku’s of Windows. See KMS Host Keys to Products Activated for more information. I am going to discuss one of the most common issues we see in support about KMS activation.

Issue:

When you try to activate a computer you receive the following error code: 0xC004C008. This error code means the following:

Cause

The common issue we see in support is that customers will use their KMS host key to activate individual KMS clients. With Windows XP/2003 a volume license key was used on each computer when you install. So when you apply this same process to Windows Vista, Windows Server 2008, Windows 7, or Windows Server 2008 R2 you will encounter this issue.

The KMS host key should only be installed on your KMS host. The key allows for 6 activations on different hardware and 10 activations on the same hardware. This is so that you can rebuild your KMS host or move the KMS Host functionality to a new system. Everything will appear to work until you reach that seventh activation.

Correct Steps for setting up KMS host and KMS clients.

Note: These are the basic steps. For additional information see the Additional Resources at the end of this blog.

1. Select a computer that you want to be your KMS host.

2. Windows Vista, Windows 7, Windows Server 2008, Windows Server 2008R2, and Windows Server 2003 can be KMS hosts. Which OS you should use depends on a number of factors. Generally we would recommend either Windows Server 2003 or Windows Server 2008R2 so that your KMS host can support Office 2010 activation in the future. Install the Operating system from volume license media. You should not be prompted for a cdkey

At cmd prompt type the following

Slmgr.vbs /ipk <KMS host key>

The /ipk installs the key. Note if you need to change your key. For example change from a KMS_B to KMS_C key you must restart the SLSVC service (Vista/2008) or SPPSVC(Win7/R2).

Slmgr.vbs /ato

The /ato activates the computer. You must activate the KMS host

4. Install the KMS client computers by using volume license media. You should not be prompted for productkey during installation

5. By default these KMS client computers will query DNS and locate your KMS host and activate

Terminology

KMS Host key: This is the key that you obtain from Microsoft for your contract

KMS Host: This is the computer that you have designated as your KMS host

KMS Client: This can be Windows Vista, Windows Server 2008, Windows 7, or Windows Server 2008 R2 computers that you are trying to activate by using KMS.

Resolution

1. First, you must have your KMS Host limit increased so that it can support additional activations. For information about how to reset your KMS key see the following document:

MAK and KMS Volume License Keys and Their Activation Limits:

2. Identify those computers that were incorrectly activated by using the KMS host key which in turn has turned those computers into KMS hosts. The easiest method is to run the following command to output VLMCS DNS records

nslookup -type=all _vlmcs._tcp>kms.txt

If you goto these individual machines you double check this by running the following command

Slmgr.vbs /dlv

I have highlighted some important information in this output. If you see “Key Management Service is enabled” then you know this computer is a KMS host. You can also see the channel of the key that was used to activate the computer. In this example the KMS_C key was used. See KMS Host Keys to Products Activated for information on the different types of keys. The partial product key is also very useful to determine what specific key was used.

3. Re-establish computers as KMS clients either using VAMT remotely or manually on the device itself.

If you have administrative rights to the computers and the computers have WMI enabled in the firewall then it is possible to use the VAMT 2.0 tool to reset these computers remotely.

A. Download and install the VAMT 2.0 tool

B. In VAMT console click “All products”

C. Enter the computername or IP address

D. Right click the computer and choose “Update status”

E. Right click the computer and choose “Install Product Key”

F. Click “Install a KMS client Key”. Note: This is installing the KMS Client Setup Key

Once the device shows the key type as ‘GVLK’, then it has re-established itself as a KMS Client.

If you cannot use VAMT 2.0 you can also reset these machines back to KMS clients manually by logging on to them. Type the following at elevated command prompt

Slmgr.vbs /ipk xxxxx-xxxxx-xxxxx-xxxxx-xxxxx

Where xxxxx-xxxxx-xxxxx-xxxxx-xxxxx is the KMS Client Setup Key for the edition installed. This will make these computers be KMS clients and look for a KMS host.

4. In order for this change to can either reboot the computer or restart the licensing service

Windows Vista/2008(Software Licensing)

Net stop slsvc

Net start slsvc

Windows 7/Windows Server 2008R2 (Software Protection)

Net stop sppsvc

Net start sppsvc

Note: If you don’t restart or reboot the computer may continue to register itself in DNS as KMS host

A KMS client will look like this. I have highlighted some important information. You can see that this is a Volume_KMSCLIENT Channel. You can see it is using the default key. See KMS Client Setup Key for the default keys. You can also see what KMS host has activated the machine.

5. Open Microsoft DNS MMC or your 3^rd party DNS management tool

6. Using the nslookup output as reference locate srv records for those machines that were incorrectly setup as KMS hosts. For example you can see 2 KMS hosts listed in this output (2008KMS and 2003KMS)

7. Delete the records for those computers that were incorrectly setup as KMS hosts so only your approved KMS hosts are listed.

Note: To prevent this from occurring in the future you can create a security group that contains your approved KMS host computers and set permissions on the _VLMCS record so only that group can update it.

Additional resources

Volume Activation Portal: http://technet.microsoft.com/en-us/windows/dd197314.aspx

How to troubleshoot Volume Activation error codes on Windows 7, Windows Server 2008 and Windows Vista-based computers

MAK and KMS Volume License Keys and Their Activation Limits

Top 5 Product Key Activation Challenges IT Pros Encountered and Solved

Microsoft Activation Centers Worldwide Telephone Numbers

KMS Client Setup Keys

KMS Host Keys to Products Activated

Scott McArthur
Senior Support Escalation Engineer
Microsoft Enterprise Platforms Support