How can I stop HP Scheduler, HP Event Handler, and HP Rules Processor from running from startup? What do each of these things do? Thanks.
Stuff from a printer, eh? Go to System Preferences, Startup Items and see if they're there. If they are, remove them. If not... try the preferences of the apps themselves.
Do you have a HP printer?
Yes.
I am not sure, as I ditched my HP a while ago ... but you may have problems with the printer if you disable those items.
It's just that they take a lot of RAM. But I don't want to take any chances.