Business Support

How to Repair or Reinstall Avast for Business

The client/cloud server communication is completed using the following ports. To ensure proper communication to the cloud portal please make sure all ports below are open and also the whitelisting of *.avast.com

  • http/80 (updates)

  • https/443 (FFL encryption key negotiation)

  • TCP, UDP/ 443, 53 for secure DNS

  • *.avast.com

  • 77.234.40.0/21 Update servers

Repair Avast

  1. Save and close/exit/quit all open software programs/work
  2. Open Control Panel
  3. Go into Add/Remove Programs or Programs and Features
  4. Select Avast product
  5. Click the “Uninstall/Change” button
  6. Click the “Repair” in the left panel
  7. Click the “Next” button
  8. Repairing may take several minutes
  9. Select “Restart”
  10. Click the “Finish” button to restart computer immediately

Clean Reinstall Avast

  1. Save and close/exit/quit all open software programs/work
  2. Open Control Panel
  3. Go into Add/Remove Programs or Programs and Features
  4. Select Avast product
  5. Click the “Uninstall/Change” button
  6. Click the “Uninstall” in the left panel
  7. Click the “Next” button
  8. Uninstalling may take several minutes
  9. Select “Restart”
  10. Click the “Finish” button to restart computer immediately
  11. Download/run the Avast Uninstall Utility at https://www.avast.com/uninstall-utility
  12. Restart computer again
  13. Open “Program Files”, “Program Files (x86)”, and “ProgramData” folders and verify all Avast subfolders have been deleted.
  14. Log into https://business.avast.com
  15. Click on the  “Add new devices” button
  16. Click on “Advanced settings”
  17. Select desired “Installer type”
  18. Choose desired options (we recommend selecting “Full (device can be offline when installing)”
  19. Click the “Download” button
  20. After downloading and before installing Avast, right-click on the file and select "Properties". If there is a Security option at the bottom, please unblock the program as shown in the screenshot below:

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