title: Is it possible to allow only one instance of project in Visual Studio 2010
body: <p>I'm using Visual Studio to code on one project. Sometimes when playing around with dual monitors and multiple applications, I overlook that I have the project already opened up. Hence, I open another Visual Studio and make changes to the project. The problem is I often work on the same files that were open in other Visual Studio. Then when I start closing everything I have a problem knowing whether one Visual Studio had any changes done that the other Visual Studio is now going to overwrite.</p>
  <p>Is there a way in Visual Studio to allow only one project instance to be opened up across all Visual Studio's open? I often work on 2 different projects at a time so limiting Visual Studio to only one instance isn't applicable for me. I work alone on those projects so there's no one that will be modifying files. Just me and my Visual Studio.</p>