Double click on Visual Studio short cut
Well, for some unfortunate reason double click to visual studio 2010 shortcut does guarantee it will work all time.I had this situation n-no of time before and today.I wish I would know why and this can be reproduce easily on any windows 7 enterprise OS.
Please comment if you aware of any trick to this 
Thanks,
Suresh Behera
www.sureshbehera.com