No hardwired internet access after upgrade to 10 or rollback to 7

[Sheila Kapes]

Upgraded to 10 last week. Lost my U-verse internet. Diagnostics says I need to plug and ethernet cable into this computer. Changed out all cables. Problem persisted. Rolled back to 7. Same problem. Googled for solutions, tried everything suggested. - uninstalled Realtek PCIe network adapter and let plug and play reinstall it, installed new driver, reset Win sock and IP stack, disabled firewalls, uninstalled anti virus software. Still nothing. ATT says everything looks great on their end. Device manager says Network adapter is working fine. No "yellow triangles, just a big red X on the LAN saying "not connected and no connections available." Wireless is working fine in the building but I don't have a wireless adapter on my desktop. Help!

 

[Trouble]

Believe it or not, I've ran into this exact thing a couple times in the not too distant past.
After doing pretty much what you've done, especially since the computer is telling you that you need to connect the cable with the "big red X"
It was one of the 8 copper contacts inside the female RJ45 jack on the back of my computer, although it could just as easily be the same thing on the switch port of the router at the other end of the cable.
Good luck getting it to pop back up for you..... a nice bright penlight, magnifying glass and dental pick did the job for me.