Eddy
2
What scanner do you mean? You mean the drivers for your scanner? If so there is no need to disable Avast. But if you really have to disable Avast (not likely) you can just right click the blue ball with the “A” and choose “stop on-access”
To enable it again click on the “on access guard” and when it has opened, choose start (begin)
I sure would recommend to download/install with Avast enabled.