I have an elderly, not very tech savvy friend whose Windows 10 Home laptop's internet access become restricted. He was having a hard time installing some new software (not sure what it was), so I offered to remote in to help. Windows assistance wouldn't let me in, so I had him run ipconfig to get his local address and had him change his internet IPv4 preferences to keep that local ip address (predicting that we would have to go into the router and do a port forward). Since we couldn'g get access to the router (he didn't remember the pw and it wasn't the default), we bypassed the router and went straight to the modem.
Google search works, but links often don't. I even had him try to access my personal ftp server, but the address doesn't resolve, even after trying to change his DNS servers to both OpenDNS and Google DNS. He's located in another part of the country from me, so I don't have physical access to the computer, other than telling him what to do.
Here's what I've done:
1) I was able to remote in when we plugged the laptop directly into the modem. (He is normally wireless, but was behind a router's firewall that wouldn't let me through). When I was there, I couldn't run Malwarebytes or Spybot (clicking on them saw them pop up in the Task Manager, then nothing), so we rebooted into Safe Mode w/ Networking and I ran them and found nothing. I also ran SFC, which said it found some items, but didn't fix all of them due to possible conflicts. I also installed Avast at that time, since he didn't have any virus protection running. Prior to installing Avast, I could not start Windows Defender.
2) After Safe Mode, we rebooted and ran reran Malwarebytes, still nothing. Windows appeared to be working and connecting to the internet (various websites and even my personal ftp server). I had Avast run a boot scan, as well. Things appeared good, although I was surprised that none of the scans turned up anything.
3) After disconnecting from the modem and going back to wireless wi-fi, the problem continued. I had him boot into safe mode and run Kaspersky scanner. All it turned up are miscellaneous IE settings. I had him open the hosts file and there was nothing added. I had him look at his IPv4 settings and his default gateway was missing. I had him re-enter that, but no change.
4) We restored the IPv4 settings to automatically obtain the local IP address.
So I am at a loss. Nothing is showing up in any scans, yet he is not able to get beyond Google.
Thanks for your time!