How can I boot with only system software active?
How do I boot my system with only system software active?
How do I boot my system with only system software active?
What system, on what Mac?
Remove everything from your User log-in items in System Preferences.
If you stated why you want to do this or what you want to accomplish, perhaps someone might offer a suggestion that would satisfy you. If you're really set on mucking around with things
http://hints.macworld.com/article.php?story=2014071314080450
How can I boot with only system software active?