Suddenly Visual Studio now builds and deploys EVERYTHING

I've been using Visual Studio for years. When I press F5 or Ctrl+F5, or press the green arrow button, I expect it to build and run the Startup Project and its dependencies. However, suddenly today it builds (and deploys to the mobile device, if it's a mobile device solution) every single project instead.

I tried several different sln files, same thing happens for each one.

Also, 开发者_StackOverflowwhile the debugger works in desktop projects, in mobile projects it simply states "unable to start debugging".

Anybody else had this problem?

I found one workaround, to right-click a single project and choose Debug | Start New Instance. (However, there is no option to start without debugging.)

You don't say which version of Visual Studio you are using.

In Visual Studio 2010 take a look at Tools | Options | Projects and Solutions | Build and Run | "Only build Startup projects and dependencies on Run". Is that item checked?