parental controls and time limits

I recently purchased a new computer that has Windows XP Pro. I also now have high-speed cable internet. My daughter uses AIM (AOL Instant Messanger) to chat. Previously we had an AOL subscription but I cancelled it. In AOL there were parental controls to set a daily time limit for a user, to limit the time that they could be on-line. Is there any product that I can use to limit her on-line time?