Internet is connected but explorer doesent work

OK I have a huge problem, I have internet on my comp. it works when I play online poker, but the yahoo and IM and my internet doesen't and it workes if I restart the computer, but only for about 5-10min but if I close the internet or come back later it doesen't work but my other computer works just fine and this computer is the one feeding the other the internet connection so it is just this computer and I checked 4 virisus and 4 everything even uninstalled most programs and it is still not working right but remember the internet still works on the other computer and the connection is made but explorer or netscape isn't working and it happen only minutes after I installed whireless internet which also works just fine all the computers work fine but this one
I NEED HELP!!!!!!!!!!!!!!!!