Under a specific circumstance a test may be automatically checked out for edit from TFS just by opening it. The condition is as follows:

1) Two people are working on the same project at the same time using TFS as source control
2) User A stores the project at Path 1 on his computer
3) User B stores the project at Path 2 on his computer
4) User A checks in changes to a test
5) User B Gets Latest
6) User B opens the test that user A just checked in

Result: the test will be automatically checked out for edit by Test Studio. User B did not make any changes on his own.

After studying what is happening, Test Studio is updating the Profiler Configuration Path in the test for the new location of the test.

The only way to prevent this is to manually/deliberately update the test to use the same hardcoded full path of where to store the Profiler Configuration of the test(s) from the Performance tab in Test Studio.