A screenshot of the message may help.
You can attach an image file of the using the 'Attachments and other options' below the reply window. Click it to expand.
What was it that you were trying to do (or was this just rebooting) ?
As far as protection goes, if you were unprotected, the tray icon should indicate this, if in fact you have a tray icon ?
The Windows Defender Security Center should also indicate if you are protected. The windows security centre could also run Windows Defender if Avast isn't running.
