stop hacking?

how do i stop someone putting a disk in my computer with a startup file and overriding my startup program?

Firstly, a cursory glance at the first or second page of Ask the Pros would have given you that answer.

Secondly: http://www.computerc...p-disk-booting/

From the looks of it, though, you cannot stop it in-game, so on a server, you are pretty much stuck. Just, you know, make a copy of your own startup programs and load from the disks yourself. That way, a: you will know if someone left their grief-disk in your machine and b: Your startup program is aways first.

A look in the tutorials section would also tell you how to do this. Or a search.