On this recommendation, both I and my husband installed Avira on our Windows 10 desktop comps. Then we both had the same problem - the computer could not shut down! Everytime either of us clicked shut down, the computer immediately sprang back into the Windows login screen. I searched the Net for answers but found none. I tried temporarily disabling most of the Avira processes, but still - no shut down. So I uninstalled it. So did he. Angry at the waste of time now. (Avira also installs a lot of bloatware, including a near-hidden process called AV Launcher. You can neither select nor disable it. Goodbye Avira.
OK, thanks. That's good to know. Can I ask -- did you download the Avira installer from the Avira website, or from a third-party website?