An Internet Problem

Not to recently, my Internet has been annoying as hell, I'm hoping y'all could help me out. On my PC Vista, it says I'm connected to the Internet, but when I attempt to use it, it claims I'm not connected. The problem started when my dad was screwing with it, he messed it up somehow.
The first thing I tried was to reset my router and IP from the computer. Failed. Next, I tried to unplug the modem and plug it back in. Still nothing. Ironically, the Mac laptops are able to use Internet, but I have to turn the Internet off and on before I can use it on the labtops. I'm pretty sure something's wrong with the router or the modem, because that's what my dad was messing with.
The first thing I tried was to reset my router and IP from the computer. Failed. Next, I tried to unplug the modem and plug it back in. Still nothing. Ironically, the Mac laptops are able to use Internet, but I have to turn the Internet off and on before I can use it on the labtops. I'm pretty sure something's wrong with the router or the modem, because that's what my dad was messing with.