It would help a lot to know what operating system you are on. It may also require administrative privileges. Plus you need to think about what you want to do if it is accidentally killed.

One trick that I've used to solve these problems is to have a cron job that tries to start my program every 5 minutes if it isn't already running. That is great if you are on Unix, and isn't hard to set up. Just use the crontab command with a line like this:

*/5 * * * * /path/to/your/command and args > /dev/null
[download]

On Windows you can use the Windows scheduler for this instead.