Have you also had him, with his pc off the whole time, unplugged power to both modem and router?

If this doesnt fix the issue outright, do it followed by a full reinstall.

And no, a system restore doesnt' count. gotta go full install from scratch, full slow patch download.

If a pc powercycles midpatch or a power surge occurs, it can hose up a patch. Not many times can you recover without a full install all over.