Set User Logon Hours

You can restrict a certain user to only use the computer at a certain time interval. Let's say you have a username called Bill and you want Bill to access the computer only from 9AM - 9PM from Monday through Friday. You can do this by going to Start->Run and type in net user Bill /time:M-F,9am-9pm. For 24-hour time, you can replace the time with 09:00-21:00 instead. This will only allow the user to login during those hours on those days.