Ok, finally lost connectivity. Notables: Trouble-Shooting 1) NIC lights are normal - solid orange (speed) and flashing yellow (activity). 2) Modem lights are all normal. 3) Did a "ipconfig" command, and it shows the IPv4 Address, Subnet Mask and Default Gateway (screenshot below). 4) All ping test of various internet sites shows normal ping results (screen shot below). Actions 5) I disabled Bitdefender and the NIC. 6) Rebooted computer - didn't reboot modem. 7) After Windows came back up, I enabled the NIC card with connection via Cat5 cable. 8) Left Bitdefender disabled. 9) Have an internet connection. Will run in this configuration and see if I lose the internet again. Probably is Bitdefender ... time to dump it. I have Window Defender built into Windows 7, so might try that instead if this test shows no more lose of internet. If it still does, then I'll uninstall Bitdefender.