Horrible connection/possible driver issue?

I recently finished building my first PC and I had done all the driver updates. For some reason my PC will not get the internet speeds like my other computers in the house are getting. Im running a gigabyte GA-Z77x-UP4 TH motherboard with windows 8 OS. I went to gigabyte website and download and installed the updated driver for the LAN. Anyone have any ideas what could be causing me to get a horrible internet connection.

I did a hard wire from the modem to the PC......still slow speeds.
I changed the Ethernet cable...still slow speeds.
Rest the modem and router...still slow speeds.

Any help would be appreciated

Thank you
John