I have recently built my computer, 3 months and have had the internet working. Recently it stopped working and the port in the back isn't even lighting up. I don't think anything happened to make this happen, but have been trying to trouble shoot and still cant figure it out. Thanks, max.
First, did you try a replacement patch cable from your router to your PC? Next, open the Device Manager and expand [+] Network Adapters and right-click on your 'NIC' driver select Uninstall and either reboot or click Scan for New Hardware.
IF that fails then go to the MOBO's website download, Uninstall per Device Manager, Install the NEW driver. IF that fails then 'some' MOBO's have listed in their drivers a 'Ethernet Diagnostic Utility' download and run the test.
I fooled around w/ the router and cable and its neither of those, tested all the same stuff on my roommates computer. The MOBO is p7p55d-e Pro. I'll try fooling around w/ the stuff you recommended and reply if it works now or not. Thanks again.