In Windows, you can temporarily disable all Avast shields by right-clicking on the Avast icon in the taskbar and hovering your cursor over “Avast shield controls”. You can disable all shields for 10 minutes, 1 hour, or until the computer is restarted. See my instructions above for more details.
You can also disable the shields from Avast’s main interface by clicking on “Protection” followed by “Core Shields”. This option allows you to disable each shield individually, and you can also choose to disable them until you want to turn them back on.
Note that in Avast’s Mac app you don’t have the option to disable shields for a defined amount of time — you only have the option to turn the shields off until you manually activate them again. On Macs, disabling the shields can only be done via the main Avast interface.