when im virus scanning and the anti-virus finds a trojan or virus, it pops up a new window saying that a virus was found. In the process of doing this, it totally pauses the scanning of my computer until i choose what to do with the found virus. What do i have to do to change this setting so that when i run my virus scan i can just leave my computer without having to worry that a virus is found and that the scanning has stop?
Hi and welcome to the forum.
Well if you have avast Home edition, you can’t make this kind of setting.
It’s because avast default answer upon virus detection is to ask you what to do with the virus found.
If you have Pro version (which btw is highly configurable), do the following:
Enable Enhanced User Interface, Choose Tasks & Choose the type of scan that you want to perform. Right click, go to Properties\Virus Page & Set the exact response that suits you.
Pro version of avast is much more configurable and therefore much more coveniant. But don’t get me wrong, in avast Home you’re not deprived of any major virus scanning and dealing with virus functions. Thanks to courtesy of Alwil Team 
There is another way 
right click on the avast icon->start avast virusscan->click on the menu button (that looks like an eject button(standart skin))->Schedule Boot-time scan->click on the checkbox advanced options-> then change Ask for action into delete infected file->Schedule
then restart the PC and you can do something else while the computer does his work. (this is not 100% Guarantied. Sometimes files can’t delete files)
You can’t delete them with the Home version, but you can have them moved to the virus chest.
Click on Standard Shield and then on Customize.
Go to Advanced tab and select Silent Mode and the default answer No.
Personally I don’t use silent mode, because I want to know what is going on with my system. If someone is getting so many warnings of virus infection, infected emails, etc. that they become intrusive, then it is time to review their security practice - filter emails at source, delete from server rather than download them, sites they visit, etc.
Leave the file in the chest for a week or two (it can do no harm from there) to ensure no adverse effect from being moved to the chest. Then scan the file again in the chest to ensure it is still detected as infected and if so delete it from the chest.
Click on Standard Shield and then on Customize. Go to Advanced tab and select Silent Mode and the default answer No.I was quick on response. Didn't occur to me at first.
Personally I don't use silent mode, because I want to know what is going on with my system.
Me too.
Yes, Silent mode can be very useful (and frequently forgotten), it is a double edged sword having a down side also, not knowing what is going on with your system. For a well protected system that is clean to start with there really is little need for Silent Mode (IMO).