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!