Windows 7 Professional: I can no longer connect directly to a switchport/dataport from laptop by ethernet cable. However, I CAN connect an ethernet cable from the laptop to the LAN port on my Airport Express, which has an ethernet cable from the WAN port to the switchport/dataport.
If connected through Airport Express, no problem.
If connected directly, it will always be connect to an "unidentified network" and have "no internet access".
I'm sure this is a simple fix, and I'll probably smack my forehead when I see the answer.
Uninstall/ reinstall the Network adapter of your laptop. Go to Device Manager then under Network Adapter uninstall both of the device you'll see there then reboot your PC and it should reinstall it back while restarting. If this doesn't work download and install the Network Adapter drivers from the support site of your laptop for both LAN and Wireless.