I installed avast! at the end of last week and set up a daily scan for 1200hrs. I did not start the computer yesterday. I switched it on this morning for an hour or so, and again this afternoon for three hours until now. I expected avast! to run a scan in these periods for yesterday and today, but none ran. Have I missed something in the set up?
It is possible the OP was referring to 'configurations/settings in Avast.
Also one might want to try a “Repair” via Contol Panel/Add and Remove…select Avast and scroll down to select “Repair” before an uninstall/reinstall process 
Bob Hawkins,
Welcome to the forum. 
You do not mention what product of Avast you have (Free, Pro, AIS). Regardless, there is no reason to scan your system daily since Avast is constantly scanning your machine in the background while your machine is on. In addition, you would not want to do a scan until Avast does a definition update. So if you are scheduling a scan prior to a definition update, this is fruitless.
Most users do Quick scans once a week, Full scans once a month, and a Boot scan only when you have an infection that the normal scan can not remove. The scans are all dependant on the user’s usage. I personally do manual scans, but some people prefer scheduled scans.
So you may want to think about how often you are scanning since it appears to be too much since Avast is already scanning in the background. Let me know if you have any questions. Thank you.
Most users do Quick scans once a week, Full scans once a monthand some don`t scan at all, but use the screen saver scan ;D
SafeSurf
I thank you for your informative and constructive response. I have the Free version. I downloaded and installed it just a few days ago, having used AVG for four years. I like the look and feel of avast! At the same time, I am trying to set it up in the best possible way, so I appreciate your advice and shall follow it.
Your welcome.
Give it a try for several days. If you have additional questions, post back to this thread.
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