Lately I had a problem (Could not load type '...' from assembly '...') with my test project (unit-test in Visual Studio 2010), so I tried (after looking for solutions here) deleting it and rewriting it. I deleted it by right-clicking on the project in Solution Explorer and choosing 'Remove'. Nevertheless, I can see that the project still exists, if I am looking in the folders (of the entire solution), through windows...
How can I correctly and completely delete the test project? (I have made a backup...)
Removing it from the project structure just modifies the solution file (.sln). After removing a project it's not anymore listed in there and the reference is gone.
So removing a project from the solution just removes the reference to the project. If you'd like to remove it entirely, delete it manually from its old location on the disk, as well.