DNS error while Activating Windows server 2008

I have installed 3 windows 2008 server so far, 2 on Virtual servers images. I have faced one constant issue with all 3 server,

If you get an error saying

A problem occurred when Windows tried to activate.
Error Code 0x8007232B.

Follow these steps to resolve it.
Open Control Panel
Open "System"
In the "Windows Activation" section
Click on "Change product key" link.
Enter your old product key you used during the installation.
(You can get this once you login to MSDN subscriber website. )
Once you enter the old product key, windows should automatically try to activate your Windows server and Activate successfully.

Hope these steps solves your activation issue.
-Yogesh