Re: Windows Security System Tray Icon
Britechguy’s Standard Advice Regarding Windows 10 Issues and Their Repair (docx)
Go straight to the SFC/DISM step. If that doesn't fix things, then the Repair Install step.
Brian - Windows 10 Pro, 64-Bit, Version 2004, Build 19041
A man's worst difficulties begin when he is able to do as he likes.
~ Thomas H. Huxley (1876)