Unplugged computer on friday, on monday it no longer works

Hi, a friend of mine's computer got unplugged from her router on friday, and when she plugged it back in today, everything was abysmally slow. She can't even load pages, although she can connect to AIM barely.

Apparently, when checking out her local internet connection properties, it says that she gets "limited or no connectivity" and also while trying things from the command line she received the errors of "can't connect to the dchp server" and "can't acquire a network address." MSN told her that her default gateway was not working.

She's tried connecting into the modem directly, and that upgraded her from being unable to connect at all to the current situation, as well as system restoring before the problem occurs, but no matter what her internet won't work. Help us, tom's hardware forums!

It's not just the router though, it's still just as slow when she connects directly to the modem, so I don't think reconfiguring the router will do much. Thanks anyways though, it's quite a conundrum.