The Avast Self-Defence Module in the Avast antivirus provides protection to the antivirus application itself. To solve the 'Avast setup is already running' error, you can try the following methods. How to Solve 'Avast Setup Is Already Running' Error If you try to end the task, the file may display message “The Operation could not be completed”. This file runs in the background of the Task Manager. But the most common reason is related to a file called the instup.exe, which basically runs in the background of Windows to update the virus definitions and download them. You want to know what causes the 'Avast setup is already running' error. How to Solve 'Avast Setup Is Already Running' Error.
