How to Abort an Experiment Early
Press Ctrl+Alt+Shift to terminate the E-Run application. An “Abort Experiment?” prompt will then appear, asking if you want to abort the experiment. Click “Yes” to abort the experiment, or click “No” to continue running. If you click “Yes”, then the E-Run application will terminate. Within the E-Studio application, an error dialog will appear displaying the “Experiment terminated by user” message.
The Ctrl+Alt+Shift key sequence is designed to be used during experiment development as a tool to help you quickly check various experiment parameters. When an experiment is terminated prematurely by using the Ctrl+Alt+Shift key sequence, the .edat3 data file is NOT generated and therefore it is likely that the data from the current experiment run will not be logged. The E-Recovery utility can sometimes be used to recover a portion of the data that has been collected to date, but it should not be used routinely in typical data collection sessions. This utility is described also in GENERAL: Recovering Files 
Press Ctrl+Alt+Backspace to terminate the E-Run program. Unlike the Ctrl+Alt+Shift termination method, this method of aborting an experiment will produce a data file after termination. When invoked, the currently running object will exit. Then, any additional objects will immediately be skipped and List objects will stop sampling.