Silverlight hardware-accelerated playback is greyed-out - How do I enable it?
I tried to find definitive system requirements for Silverlight but the info is pretty sparse. Check out the following requirements from the MSDN site -
http://msdn.microsoft.com/en-us/library/dd833062%28v=VS.95%29.aspx
This MSDN Blog gives additional detail -
http://blogs.msdn.com/b/rahul/archive/2010/06/09/silverlight-graphics-and-hardware-acceleration.aspx?Redirected=true
Are you the administrator for this computer? Per the message at the bottom of the dialog box, you may have to enable it on the admin account first.