I have found this link, http://social.technet.microsoft.com/forums/en-us/windowsserver2008r2general/thread/CE1A80C6-AC89-442B-8680-0CC11E3CAEC2 the question is : why I cannot use the product key which from TechNet site to upgrade the Windows Server 2008 R2 Operating System which also got from TechNet site; Windows Server 2008 R2, from Standard to Enterprise, also from Enterprise to Datacenter. By the way: I have tested by using this product key 489J6-VHDMP-X63PK-3K798-CPX3Y that mentioned by that answer in the above link, and it successed. This is the error message:

Hi, MAK keys map to multiple editions. So the underlying infrastructure doesn't accept them. If you use the KMS client key, that will allow you to proceed with the upgrade. After upgrading, you can change the key as you like. http://technet.microsoft.com/en-us/library/dd744380(WS.10).aspx Tim Quan TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Just to confirm it, do you mean I should use the KMS client key first and then change the product key to MAK key which from TechNet site? For another thing, may I know which kind of product key could work by using this DISM, it seems MAK key from TechNet Site cannot work, there must be some other kinds? May I know that?

Hi, As I know, a KMS key and a retail key can work. MAK keys do not work. Not sure about other kinds of keys. If you would like to use a MAK key, I suggest using a KMS key to upgrade the system first and then change the key later. Tim Quan TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hi, If you have any other question regarding this issue, please feel free to let me know. Tim Quan TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hello Everyone, I've Exchange 2010 already installed on Windows 2008 R2 standard edition, now we are having requirement to implement DAG and to implement DAG we have to upgrade from Windows 2008 R2 Standard to Windows 2008 R2 Enterprise. if you use this method to upgrade edition, does it going to impact any Exchange services? Thanks