How do you stop running script on my computer

You need to be a bit more specific than that. Need more details, what program, what script, etc.

What operating system are you using? As smoothy asked, what program, etc.

If you want to block scripts online, then you should be able to disable scripts in the browser settings. Or you can use an addon like NoScript for Firefox to manage which sites you allow scripts from and which ones you don't.