You don't mention which agent (UD or BOINC) or platform. For Windows, it's just a matter of adding it to your startup folder. Usually, that's something you select when you install but at worst, you can create a shortcut on the desktop and drag/drop that into your startup folder. Glad to see you want to crunch all the time. It normally won't be an issue when you're doing work unless your playing some cpu intensive game or graphics and even then it may not be noticable as both agents use the lowest priority.