if youre online, and the ethernet cable is unplugged from the router...youre on someone elses network.
have you tried resetting the modem (unplugging and plugging back in) and restarting your dads computer? or have you tried another computer directly connected to the modem? if neither of those will work then theres something going on with the signal coming out of the modem, or coming from your cable company.
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Matt

B18B1 FTW
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