Removes Steam from the per-user startup run by clearing its autostart preference (SteamApp 'AutoStartup'). Steam launches when you open it instead of at boot. Reversible.
MaxTweaks applies this tweak with one click and snapshots your original setting first, so you can revert it cleanly at any time. A System Restore point is offered before batch changes, and every tweak links to its official source.
Get MaxTweaksOfficial documentation: https://help.steampowered.com/en/faqs/view/4F62-9C8B-3F2A-7E2C