Whenever you start or restart your PC, you have to key in your username and password for the actual startup process to commence. So, if you restarted your PC and went to get a cup of coffee, you will still have to wait a good 30-40 seconds before you can start working on.
Auto Login and Lock is a handy software which could save you some time here. It will automatically login to Windows on startup and then lock Windows so that a password is still required to login. However, since the startup process is already underway, you can just login and start working when you return with your cup of coffee.