vshost can improve debugging speed but can get locked!

The vshost file was introduced in Visual Studio 2005 to make debugging launch quicker. The vshost.exe that is created as part of your application is also known as the "Hosting Process". They are not designed to be run directly or included as part of a deployment. Its performance boost comes from having an application domain already created, that the debugger gets associated with.

Sometimes the vshost file gets locked. You need to close the Visual Studio with that project opened to unlock it.