Solved Control Panel frozen & blank

I have an Acer Aspire V 11 Touch with a Celeron CPU N2840 and running WIN 8.1 and it has recently been acting strangely. Most problems have cleared up except for the Control Panel. If I reach Control Panel by any route the display freezes. Nothing on the Control Panel responds and no list of items appear and the white cross on a red background has no effect. Other parts of the computer work, and the only way I can get rid of the Control Panel screen is to use Task Manager.
When I shut down the computer after turning off everything I know about it shows "To go back and save your work click Cancel and finish what you need to". Another option is 'Shut down anyway'. And it shows this message for every shut down. Do these clues suggest what should be done? I have used restore but that fails each time saying it could be due to my anti-virus. I have AVG free that allows me to disable for 15 min or until next computer turn on, neither of which is enough. I can access the folders of the computer. I would welcome suggestions,

When I submitted my problem I hoped some expert would come up with an easy solution, but that did not happen. I looked elsewhere and found that my problem had occurred to many others. Someone had the theory that his antivirus had removed legitimate parts of WIN 8 thinking they were viruses. Eventually I decided to use the built-in Acer Recovery Management, which gave me 3 options. I chose the one that re-installed all my systems but kept data. I had to reload MS Office separately, but that was fairly easy because my ownership was easily acknowledged on my Microsoft account.The whole procedure was slow but easy. I changed my antivirus to Avast.