i have 2 computer older is win xp based and newer is windows 7 home premium 64bit machine-and it work almost perfectly.
My router is d-link dir-600,firmware is v2.01-hardware version is B1.
And my connection to internet is cable-not wireless.
My modem is 4 year old WebStar-it is from my internet service provider,comhem(sweden).
Problem is:When i turn on Parental Control with schedule(from router) my internet connection stops working-from both computers.and when i turn off Parental Control-there is no problems.
this is very stupid problem.is it my modem too old for my new system?or something else??

I don't have a clue - but the first thing I thought of was if Parental Control is set to block the Internet. So when enabled, it blocks. So I am guessing you should go into Parental Control, and have it allow Internet access during the times you want access.

Check out the Frequently Asked Questions related to 'parental controls':

D-Link - TechSupport FAQ

In particular:

Q: How do I configure the Parental Controls services?
Q: I have configured my Parental Controls, now every Web site is blocked.

Hi,
The first thing to try is power cycling your router. This essentially means turn it off for a couple of minutes Disconnect the power cable from the back of the router, wait a couple minutes and plug it back in. The router should automatically reboot and reconnect, and its entirely possible that your problem is fixed, as easy as that. Just like restarting a frozen computer.

Thanks