How to stop proceses autostarting on bootup

I've narrowed a FS9 crashing problem to processes that autostart when the PC boots up, so that when I close all of the non-essential ones in Task Manager, following that FS9 seems to run OK.
How do edit which processes are auto-started on bootup so that I don't have to close them manually in Task Manager?
Thanks for your help.

How do edit which processes are auto-started on bootup so that I don't have to close them manually in Task Manager?
Thanks for your help.
