Click Add.
Go to the folder or file that you want to exclude from the scan and click the button with an arrow pointing to the right. 
Click OK.
will scan by default all files and folders on your computer. However, you can configure it so that it does not scan certain files or directories. This is useful, for example, when you want to use, under your own responsibility, certain files all applications which considers malware. To do it, follow these steps:
Open the main window and in the Protection section, click Settings.
Click Known threats in the left panel.
Click on the option Settings in the Threats to detect and exclude section.
Click the Directories tab or Files, depending on the type of item you want to exclude from the scans.
The procedure for excluding folders and files is identical:
Click Add.
Go to the folder or file that you want to exclude from the scan and click the button with an arrow pointing to the right.
Click OK.
When you exclude a file, will scan it and if it finds out it is a threat, will ask for your confirmation before excluding it from the scans.
To delete one of the files or folders from the list of exclusions, select it and click on Delete.