I NEED HELP WITH MY INTERNET CONNECTION! ( read the details )?

GUYS ! i need help!!!!!, okay.. so I have this wireless that is from telstra , its a Thomson Getaway i think? but anyways.... so i downloaded this Mcafe Internet Security on to my computer.. then i dont know if it was the mcafe that stuffed it up , but when i downloaded that on my computer (i bought it) , my internet stuffed up???? it says on my computer that the internet is coneccted, but when i click on enternet it just goes to the page where it says ' no connection ' ??? BUT on my laptop the internet is working fine? and i didnt download the mcafe on to the laptop... the wireless is working everywhere.. except my computer where i downloaded mcafe internet security... PLEASE HELP ME??? i tried to reset the modem but it still wont work.. i did everything , i restarted the computer but its still not connecting to the intenet????????? PLEASE HELP!!!!!!!! FAST !!!! ASAP !!!!