The idea, in
device manager is to highlight the WIRED-network card, and delete it. Windows will re-install the drivers. Maybe tech support had you do that already, IDK. But if the card is not dead, a reinstall may get you network access that way too.
I have to go.
And check the cable, and make sure it's plugged into the right ports on the computer, and also (maybe a different port?) on the dsl
device if there's more than one port to use. Just some ideas to try if you haven't tried them with tech support already.