Sandbox - Web browsers
Manage these settings at: Menu ▸ Settings (gear icon) ▸ Tools ▸ Sandbox ▸ Customize ▸ Web browsers
Save trusted downloaded files - When checked, Avast does not virtualize files downloaded via Sandbox if they are verified as safe - they are saved on your computer. When unchecked, downloaded files are deleted when the virtualized session ends.
Exclusions
The checked items are excluded from virtualization, and are not deleted when you end your sandbox session.
For example, if bookmarks is checked, and you create a bookmark while running your browser in the sandbox, it is also available when running your browser outside of the sandbox.
Maintenance
Check Cache web browser files to save virtualized files for web browsers only. All other virtualized files are deleted. This improves web browser performance in the sandbox.
Cached contents can be deleted at any time, or set to be automatically deleted, to clean up disk space.