Activation error code 0xC004B100 on Windows 7, Windows Server 2008 and Windows Vista-based computers

Activation error code 0xC004B100 on Windows 7, Windows Server 2008 and Windows Vista-based computers

Error code 0xC004B100

Symptom

When you try to use a MAK to activate one or more computers, you may receive the following error message:

0xC004B100
The activation server determined that the computer could not be activated.

Cause

This issue may occur if the MAK is unsupported.

Workaround

To troubleshoot this issue, verify that the MAK that is used is the MAK that was provided by Microsoft. To verify that the MAK is valid, contact the Product Activation Call Center.

Solution:

Type slmgr.vbs –upk command to clear all product key that are present on the computer. For example, these may include the Multiple Activation Key (MAK) and the Key Management Service (KMS) key.

After you run the slmgr.vbs –upk command, you may decide to run theslmgr.vbs – dli command or the slmgr.vbs – dlv command to display the Windows Vista licensing information. However, no result is returned in this situation. Additionally, you may receive the following error message when you check the Windows activation information:

This copy of Windows is not activated. Click here to activate Windows now.

Finally, when you restart the computer, you may be prompted to insert a product key. In this situation, Windows Vista may enter reduced functionality mode.

To resolve this problem, use one of the following methods.

Method 1

1. In the Start Search box, type command prompt, right-click Command Prompt, and then click Run as administrator.
2. In the Administrator: Command Prompt window, type a command that resembles the following, and then press ENTER:
   cscript c:\windows\system32\slmgr.vbs -ipk {ProductKey}
   Note If your organization uses a KMS key instead of a MAK key, use the generic KMS key that is provided in the Pid.txt file. This file is located in the \sources folder on the Windows Vista installation DVD.
3. Type a command that resembles the following, and then press ENTER:
   cscript c:\windows\system32\slmgr.vbs -ato

Method 2

1. Click the error message that is mentioned in the "Symptoms" section.
2. Type the product key, and then follow the instructions to activate the product key.

Method 3

1. Restart the computer.
2. Log on to the computer. The Windows Activation window will appear.
3. Type the product key, and then follow the instructions to activate the product key.

source: http://itshi-tech.blogspot.com/2010/08/activation-error-code-0xc004b100-on.html