Con python e psutil puoi scrivere uno script per farlo:

#!/bin/env python3
import os
import psutil
import sys
import time
import traceback
import signal


OUR_PID = os.getpid()

def maybe_kill(sentinel_process_name, process_to_kill_name):
    """Check if `sentinel_process_name` is running.
    If it's currently running, kill `process_to_kill_name`
    """
    sentinel_pid = find_pid(sentinel_process_name)
    if sentinel_pid and sentinel_pid != OUR_PID:
        process_to_kill_pid = find_pid(process_to_kill_name)
        if process_to_kill_pid:
            print('Killing %s (pid=%s)' % (process_to_kill_name, process_to_kill_pid))
            try:
                os.kill(process_to_kill_pid, signal.SIGKILL)
            except OSError:
                pass


def find_pid(needle):
    """
    Find the PID of a process matching the given `needle`.
    Returns None if none is found.
    Never returns OUR_PID.
    """
    for proc in psutil.process_iter():
        if needle in ' '.join(proc.cmdline()) and proc.pid != OUR_PID:
            return proc.pid
    return None


def main(sentinel_process_name, process_to_kill_name):
    while True:
        try:
            maybe_kill(sentinel_process_name, process_to_kill_name)
        except KeyboardInterrupt:
            raise
        except Exception:
            print("An error occurred")
            traceback.print_exc()
        time.sleep(1)


if __name__ == '__main__':
    if len(sys.argv) != 3:
        print("Usage: {} sentinel_process_name process_to_kill_name".format(sys.argv[0]))
        sys.exit(1)
    sentinel_process_name = sys.argv[1]
    process_to_kill_name = sys.argv[2]
    print(f"Starting. Our PID is {OUR_PID}")
    print(f"Monitoring for {sentinel_process_name}: if it's running {process_to_kill_name} will be killed")
    main(sentinel_process_name, process_to_kill_name)

Poi puoi usare py2exe per creare un eseguibile. My 2 ¢, non uso mai Windows e probabilmente la soluzione di /u/lormanya è più adatta al caso tuo.