Windows 7: Parental Time Control

I want to be able to control the kids time spent on the computers from 1 main computer. has anyone found a software that works on all computers but can be set from 1 computer and updates all computers, i found 1's that i had to set up on each computer but then each computer had a 30min a day limit per child. i want 30min limit between all computers

thank you

Hi there, have a look at Parental Controls - Windows 7 features - Microsoft Windows
It has most of the features which you're looking for.

Hi i have looked into windows 7 parental controls. its not what i want.
an example would be
i have 4 computers, each computer has user1, user2, user3, user4, user5, user6, user7 & user8. i want to be able to set user1-4 30 mins per day but if say user3 needs an extra 30 mins for homework, etc. i can just add it from my main computer and it update each computer in real time.

I have been looking for ages and still not found one. i have even written to a few companies that create these and either get email saying coming soon or we dont see the point.

I was thinking along the lines of internet cafe software but i just want controls that i can control in real time.

thank you for the suggestion