Hi! I’m wondering if there is a way to get rid of the antivirus scan that starts up right when you press the button when to start your computer. I want to scan my computer manually when i want it. Some help would be nice. Thanks! 
Michioki
Hi michioki & wellcome to the forum!
Yes you can skip the startup scanning by just uncheck the checkbox called “Test memory during application star-up” in the “avast! settings…” menu, see below
The option shown by avatar2005 only removes the memory scan prior to the Start avast! antivirus, before the Simple User Interface opens and not a scan at boot.
I think you are mistaken with the schedule boot-time scan option (only for the next boot and not before every boot), which is a long scan and the scanning of running files on boot. With my avast on default settings , the standard shield on Normal, there are only about 100 files scanned on starting my system and no major delay.