It's very annoying to have the IISExpress web server close down every time you hit the STOP button in the Visual Studio Debugger.
Fortunately, it's simple enough to keep it open:
- Go to the web application in the Solution Explorer.
- Right click on it and hit "Properties" (or hit ALT + ENTER).
- Click on the "Web" tab on the left.
- Uncheck the box for "Enable Edit and Continue".
And that's all there is to it.