I have a VS 10 project using .Net 4.0 and I use lots of stuff that do require 4.0. I created a VS Setup project added the primary output from my project and built it. I then installed it and everything worked fine. A few days later I am ready to do a new build so I rebuild my project and then the setup project. Now when I run the msi it tells me that .Net Framework 4.0 is required.... I figured I screwed it up so I just create a new setup project, and that works fine. But again a few days later (restarted VS in there probably and maybe even the computer) I rebuild and get the error telling me that .Net 4.0 is required. I did it a few times just to verify and it consistently happens and I cannot figure out why.
The project I am building and installing has a windows service that is set as the startup project. I will switch that to a console app object for local testing purposes and build and test the project (not the setup project). This is the only thing I can think of that may be impacting the build, but again, I cannot figure out why.
Any help is appreciated.