Test Execute | Cannot Launch another instance of this application

Ok, finally  I had the chance to try, here is the scenario.

1) On my computer only test executor is installed. I also added its bin directory to the path under environmental variables of the computer.

2) I created a simple test, only logging out the message as "Test is done", that is not a long test. One unit and under the unit, there is only one routine -> testRoutine1

3) I run the test via test executor, test is OK, I can see the results.

At this point, if I try to run the same test again with same testexecutor command, I got the error  " Cannot Launch another instance of this application"

4) When I check the windows tray at the bottom left I see the small test executor icon, meaning, the error is right and test executor did not close itself after I run my test.

See the picture, please.

5) If I want to run my test again, I have to go to tray, left click and exit test executor. 

ı assume I miss a point, that helps the executor to stop its own process / task, Then if I want to run another test, I should not get the error "Cannot Launch another instance of this application"