The following error occurs trying to use a retail edition of Office Professional Plus 2010 on a Windows Server 2008 Terminal Services:

This copy of Microsoft Office 2010 cannot be used on a computer running Terminal Services. To User Office 2010 on a computer running Terminal Services, you must use a Volument License Edition of Office. 

To fix the problem, go to your MSDN subscriptions account product key page and get a key for “Terminal Service enablement for Office 2010”. Then navigate to Control Panel, find Office Pro Plus 2010 and enter a new product key. More info is available on this page: http://support.microsoft.com/kb/983443/en-us.