Window10 icons on tool bar line at bottom disappeared

When I clicked power icon to system off ii found out one word file had not been saved so I clicked the cancel option then suddenly all the icons on tool bar line at bottom was disappeared and dozens of white blank icon was created instead.
Problem was that I can browse curcer but didn't work anything apart from norton antivirus programme which shows safe green V light

Could anybody put out my misery?

Thanks appreciate your time

Chalee

For additional information.
All icons in task bar was disappeared except window logosobut it doesn't work either. I tried ctl+alt+del?task manager?new task?type services.msc ?enter?application identity?sart
But it was not successful and keep showing me stop/restart options