I am not sure what you are trying to accomplish, but in your screenshot you are not actually testing for file exists. To perform a test that actually continues when the file exists you need to pass control (yellow line) from the True connector, Passing control from the top yellow dot will cause control to pass whether the file exists or not.
Using File Open to launch an exe is not the proper way to start an application. There are several ways to start a process but this would not be one of them. For starting a process without injection use the System.Diagnostics.Process object. For starting with injection you can change the path of an adapter and start the adapter.
A little more information would be required to completely answer your question.