Hi Mrs R,
'System Restore' is a feature in recent versions of Windows that can put a system back to where it was - i.e. prior to when something undesirable has occurred.
I don't know which ver of Windows your are running - as in 7 or 8 or 10 - so instructions on how to perform a Restore may vary slightly for each, but if you do a net search for 'How to System Restore Windows (version number) you should find plenty of walkthroughs.
Here's one:
http://windows.microsoft.com/en-gb/w...s-and-settings
If you know w
hen the young miscreant did whatever he did, you can restore Windows to the restore point prior to that.
It may even list that event as a restore point - choose that one if so.
if you do that, and physically remove anything he has plugged in (though I assume it is a virtual network adapter of some sort?) it _should_ do exactly as you wish - i.e. put it back to how it was before.
HTH
Edit:
Ouch - just read your last post above - OK, you tried that already - I shoulda guessed you might have been on top of that option.
Sorry, that is a bit of an ugly mess by the sounds of it - I'd MAKE him clear it up. !