IN MY PC I CAN'T ACCESS INTERNET

Hello,
IN MY PC I HAD CONNECTED INTERNET USING GSM MODEM AND AS WELL AS THROUGH USB MODEM IT SHOW THAT NET IS BEEN CONNECTED BUT THE RECEIVED IS TOO LOW AND IT SHOW IN INTERNET EXPLORER THAT SERVER CANNOT DETECT BUT WHEN I CONECTED THE MODEM IN ANOTHER PC IT IS WORKING PROPERLY WHAT MAY BE THE PROBLEM ?