a timer for the PC - screen tme for the kids

When my kids were kids, I used to install VNC and say I would be watching what they were doing so they had better behave. I seldom did. I doubt you could get away with that these days. You say "PC" so I assume MS Windows. It has a pretty good task scheduler that do all sorts of nasty things. (at the last place I worked someone who left because they said he wasn't skilled enough to promote scheduled a task on a server to send a salacious e-mail a month after he left) The "simplest" is to create a logon event that's does "shutdown /t nnnnnn /s" where "nnnnn" is the number of seconds of play time. You can set it up as a scheduled task that runs as administrator at logon and make them restricted users so they can't cancel the shutdown... ... but they can always switch on again, so you would need more logic to check the time at logon and log them off its outside permitted hours.... it's such iPods WiFi, Dave