Visual Studio 2010 error: “Project Target Framework Not Installed” when opening a .NET 4.0 project

Question

I am experiencing a rather disconcerting issue with one of my development machines that I hope someone can advise me on.

I have a large Visual Studio 2010 VB solutio

Answer 1

Similar problem reported on Social MSDN. The unhappy solution was:

I solved the problem myself by doing the following steps:

a) because my problem occurs the first time after a Windows Security-Update for VS 2008, I´ve done a System-Recovery to get the state before the mentioned Win-Update

b) then I´ve un- and re-installed VS 2010 (including .NET Framework 4.0)

I'm just posting this because I just ran into this same error.