Manage these settings at:
Settings ▸ Troubleshooting

Advanced users can change these settings to resolve some specific problems.


  • Enable rootkit scan on system startup - Normally Avast scans for rootkits when the operating system starts to detect viruses that cannot be detected after startup. Unchecking this box disables the scan for quicker startup, but an active virus may not be detected.
  • Enable raw disk access during Avast boot-time scan - During a boot-time scan, Avast uses a special method to access the raw data on the hard disk to check for potential viruses.
  • Skip checking of digital signatures of infected files - This refers to when a threat is detected in files containing a valid digital signature, including system files. When this box is unchecked, Avast reports but does not take any action for files which contain a threat but have a valid digital signature. This is unchecked by default to exclude trusted files from being deleted or moved if a threat is detected. When this box is checked, Avast takes action for all files containing threats including those with a valid digital signature.
  • Enable Avast self-defense module - Avast contains self-defense features to prevent virus attacks from modifying or deleting critical antivirus files. Unchecking this box turns off the self-defense and allows Avast files to be deleted.
  • Load Avast services only after loading other system services - Avast service normally loads early in the boot process but in some cases this can slow down the system temporarily after startup. Check this box to delay loading Avast services until after other system services load, but this slightly increases risk because your system is unprotected for a short period during startup.
  • Do not use Chrome as Avast default browser - Check this box to use your default browser instead of Google Chrome when Avast opens a webpage.
  • Limit program access for Guest account - A user logged in to your computer as a Guest cannot access or modify settings for Avast.
  • Enable hardware-assisted virtualization - This is a more secure way to launch virtualized processes. If this box is checked, potential threats opened in Sandbox cannot modify your computer or files.

Restore factory defaults

Click Reset now to restore your Avast settings to the original default settings. After resetting you can adjust as needed.

Redirect Settings

If the standard ports are not used for your email and web communication, specify here which ports are used. This is important to ensure that your emails and web browsing are monitored by Avast.

For the Web, Avast normally monitors only communication through port 80. If you use a proxy server to access the Internet you must enter the port used to connect to the proxy server so that communications between the proxy server and your computer to be scanned. Only enter the ports for HTTP traffic, not for ICQ,DC++ etc. For Mail, the default ports are the standard port numbers for the four basic email protocols. If you use a different port (or ports) you must enter them here. Use commas to separate multiple port numbers in the list.

  • Ignored addresses - Enter server addresses or ports that you want to exclude from scanning.
  • Ignore local communication - When this box is checked Avast does not scan internal system communication on your computer. When this box is unchecked, all communication is scanned to increase security but may slow down performance slightly.