Can't get online after replacing faulty hard drive and re-installing windows 7 on...

...my samsung laptop? My hard drive stopped working on my samsung laptop so i replaced it, i also re installed windows 7 but now i just can't get online, even when i use ethernet cable. Its probably just some setting that i have overlooked but its driving me mad, any help would be appreciated. cheers
ethernet controller, network controller and pci simple communications all have a warning sign next to them but i cant get online to update the drivers