Tethering suddenly stopped. samsung grand neo

[blickjo1]

Hello:bounce
I had my neo tethered to a windows 7 laptop via usb yesterday all fine and all day have been unable to use it.
Have tried rebooting both, reinstalling and run virus/malware on both. Cleared cookies/cache on both

It started after I updated avast virus software on the laptop this morning

Checked with another phone and same laptop but works fine.
My phone also works tethering another pc.

Is there any logic left in this dumb world?

 

[blickjo1]

OK it has now resolved.
I plugged it back up to a different computer with usb (just to verify it was working on that device), and yes it still worked.
And now it works again on the laptop!@@!

I have no idea what the problem was but the fix seems to be to trick it into believing in a past life.