An automated technique for switching operating systems, responsive to current context of an executing test scenario. A test designer specifies, in a process control file, a required operating system for appropriate command blocks. A test sequencer packages the required operating system name with each command to be executed, and sends that information to a test listener on a system under test. The test listener remembers the currently-running operating system, and compares that to the required operating system for each command to be executed. If a mismatch occurs, then the correct operating system is not running, and the listener automatically triggers a reboot.