Assalamualaikum wr.wb
Few days ago, I was working with our company Windows 8 Enterprise Key as we are going to perform OS upgrade for our internal PCs. I went to test our Volume License Key with the nifty Volume Activation Management Tool 2.0 ( VAMT ) , but whenever I tried to add our key to the tool I got the error message as below ( Invalid character in the product key ) , you can test it yourself with the N character :



With the release of Windows 8 and Windows Server 2012 , Microsoft released The Windows® Assessment and Deployment Kit (Windows ADK) which contains all of the tools that you need to customize, assess, and deploy Windows operating systems to new computers.
Now I will show to you can perform installation of VAMT , so you can use it for Windows 8 activation.

First of all , download ADK installation file for Windows 8 from Here



Once completed , start the installer adksetup.exe and proceed as follow :

1.You can go with either options below ( for me I will go with Install )

Install : To perform direct installation of the required feature(s) on the local system and hence streams required components download
Download : To download the required components to do installation on another system



2. At “Select the features you want to install” I choose VAMT and SQL 2012 Express ( as I have no SQL installed ) then click Install



3. It starts by acquiring the installers packages and store it at C:\Users\%Username%\Downloads\Windows Kits\8.0\ADK\Installers ( This may take sometime based on your internet connection speed )


4. Once download is completed , installer will proceed with VAMT installation



5. Then SQL Server 2012 Express will be installed



6. At last update finalization will take place



7. Now , VAMT is installed



Now , when starting VAMT console it will request specifying of its data location [ I picked .\ADK for local machine and created a new database named IT Guy DB ] , then click Connect .
Type anything in the database box (it will say the data base does not exist and will ask you want to create one with  that name, Click YES)



My new database is being created [ IT Guy DB ] , then connection is taking place



8. Once completed VAMT console is opened , connected and ready for use



Sumber: http://www.itguydiaries.net