Internet working on ony 1 computer..?

Hello,
I have a PC,a laptop and 1 fixed broadband connection without a router.I am using this connection on both the pc n laptop since many months.yesterday suddenly i lost the connection on PC while i was downloading smthing.Now the connection works on my laptop but not on my PC.The sent packets increase in a normal speed but the recieved packets dont. i tried typing stuff like "ipconfig" and flush in RUN.but dint really work.Please help me to find out a solution.thanx and also provide you email address if possible for further communication.
Thanx!!