This sometimes happens when first booting up computer. In the lower right corner of the screen there is an alert message (can't recall exact wording) indicating that there is a security breech the needs to be fixed. "Fix" is one of the words in that alert message. The problem is that the alert doesn't stay on the screen long enough. I need to be very quick and fast with the mouse, in order to get the cursor there to activate the fix before the alert disappears from the screen. The alert should remain on the screen longer, so to have enough time to get the cursor there. Multiple times, I have then had Norton 360 do a quick scan that resulted in that there are no threats. To me, this raises the question of whether the alert in lower right screen was like the ancient story of the shepherd boy shouting "Wolf" (a story that has been around since long before computers).