Use RunOne utility to run your application and ensure that only once instance of the application is run at a time.
Download RunOne.exe (16 KB).
Here is the help screen containing complete description and examples
Usage: RunOne [/H] [/M] [/T timeout] [program name] [parameters]
Command line parameters:
|/H||Run specified program in a hidden window.|
|/M||Run specified program minimized.|
|/T||Set process timeout in seconds. If the process does not finish in the specified time it is forcibly terminated.|
|program name||Name of the program file to launch. If the name includes spaces enclose the entire name in double quotes.|
|parameters||Optional command line parameters that you want to pass to the program.|
Run RunOne.exe without parameters from the DOS command prompt to see full description of the supported parameters.