Sometimes the kids are on the computer too late and rather than yelling at them I want the computer to help me out. I already have a separate user set up so they don't have admin access to the computer but I can't find how I can force only certain login times.
Create a scheduled task. Go to the control panel and find "Scheduled Tasks", then create a task to run at midnight. You have several options for the action it should take:
If you also want to prevent them from logging back on, you can use the
Not sure if this is completely what you want, but K9 Web Protection is a child's (or children's) web filtering and blocking software that is extremely configurable. You could turn off all the settings that you didn't want (filtering, word block, site block, category block), and just use the Internet time feature. You can set what hours of the day you want the Internet on the computer to be blocked, and can customize each day of the week. All settings are accessed via the web browser, and are protected by a password, which you could give to someone else and not know yourself if you wanted to completely block access. It works cross-browsers; one configuration covers Internet Explorer, Firefox, and others all one the same machine.
K9 Web Protection: http://www1.k9webprotection.com/
Did I mention that it is FREE?