I need to de-activate Avast COMPLETELY for a short time to do a test. Is that possible?
Thanks JG
You can’t deactivate Avast,but you can turn the shields off.To do this right click on the Avast icon and turn the shields off for whatever time you want.
Thank you.
I need to measure something and for that purpose I need all security software off, so it cannot interfere.
EVERYthing Avast will be turned off for the time specified?
Turning everything off is a great way to get your system infected.
The only way to not have avast! in the picture is to totally uninstall it.
This means removing it through the add/remove function and using the removal tool.
That really does depend on what the OP is proposing to test with.
If its a safe testing file and using a safe website etc then turning off avast for a specified time should not be an issue and infection would be quite rare.
It only takes a few minutes of browsing the internet unprotected to wind up infected.
If you would like to experiment, be my guest. I’ll stay safe and keep avast! and all of it’s shields active. 
If you want to do that, you should do it offline and in a lab setting, that is in a sandbox environment
and for research purposes only.
If you like to turn off all anti-malware applications to test something to circumvent detection,
or go under the detection radar, and you do not do that under the right legal settings,
know it is going to be logged and
you could be accused of an offense,
and the logs could be hold out against you.
I would not like to risk the experience!
polonus