Computer in a mess after AVG tune up

Ann, Have a look @ this AVG article (http://avgclick.me/RevertPCTchanges).
AVG Guru

I ran a one-off AVG tune up two days ago and my computer is now unrecognisable.  I can't even open basic things like
Excel or Word.  I'm on windows 8.1 and even the big icon screen has disappeared.  I click on short cuts and they all seem not connected 
any more.  I have a touch screen (which I don't use) but can't get rid of the "helpful" hints telling me to swipe in from the left etc.  It's even
changed my keyboard to US style!  Any advice welcome.

Ann, Have a look @ this AVG article (http://avgclick.me/RevertPCTchanges).
AVG Guru

Hello Ann,
We regret for the inconvenience caused. Please follow the instructions below to restore the changes made by the AVG PC TuneUp program :
1. Open AVG PC TuneUp program.
2. Click on the Rescue Center on the right bottom corner.
3. Click on Undo Changes.
4. Select and restore the changes made by the AVG PC TuneUp program.
Thank you.