Microsoft daily scan interupted

Everyday at 3 AM  Windows runs automatic tasks a clock icon appears over the white flag in task bar corner icon. Using the computer interrupts this scan and it needs a long idle period to start again. While I wait for the clock icon to disappear, Norton background tasks alert starts,  and the cock icon disappears. I know from times without anti virus  that not enough time has been allowed  to pass before the interruption.  As  far as I can see  there is no way to stop the automatic performance tasks from Norton from activating.  I did see in  the options  that you can manually run  the tasks. Maybe this will stop them from running after a set period of being idle?  I have Win 8.1 and NIS without automatic backup. It is a laptop with a Celeron duo core so tasks take much longer than my desktop computer with a Intel 5 processor.      Thanks for any help.