I was getting this error trying to open the strataframe samples.
The issue for me was that I am using VS 2008 and the Visual Studio Version Selector was getting confused (I had VS 2005 at one point).
The solution was to right click on the solution file and click open with. Navigate to "C:\Program Files\Microsoft Visual Studio 9.0\Common7\IDE\devenv.exe" and click to open. The conversion wizard runs and the project will then open.
Hope this is useful ;-) Cory Cookson
Software Developer
Occupational Health Research