How to Perform a Clean Installation of Avast Antivirus

One common issue with antivirus software is leftover files from previous installations, which can cause failures or conflicts. To prevent this, a clean installation is strongly recommended—especially when migrating from Avast consumer versions (Free, Pro, Internet Security, Premium) or legacy Endpoint Protection to the cloud version.

There are several methods to achieve a clean installation:

1. DOMAIN Deployment

If your organization uses a Domain and you are currently running the legacy Avast Endpoint Protection Suite/Plus, you can deploy AVASTCLEAR.MSI via Group Policy.
Download AVASTCLEAR.MSI: https://www.dropbox.com/s/5rpu32cnkc5fy54/avastclear.mis?dl=0

2. Manual Uninstall

You can manually uninstall Avast:

1. Use the standard uninstaller to remove Avast.

2. Reboot your system.

3. Delete the following folders:

   • C:\Program Files\AVAST Software

   • C:\ProgramData\AVAST Software

Note: Microsoft’s uninstaller often leaves residual directories to support System Restore. If you check, you’ll find folders from programs you uninstalled long ago.

3. Avast Removal Tool (Recommended)

The ASWCLEAR.EXE removal tool supports all Avast versions, including Free, Pro, Internet Security, and Premier. AVASTCLEAR.MSI, however, is only for Endpoint Protection.

Download the removal tool: http://www.avast.com/en-us/uninstall-utility

Steps to Use ASWCLEAR.EXE:

1. Run ASWCLEAR.EXE.

2. Before proceeding, disable the Avast Self-Defense Module. This allows the removal tool to run without requiring Safe Mode.

3. Uncheck “Enable Avast! Self-Defense Module” and confirm by selecting Yes to fully disable it.

4. Once disabled, proceed to uninstall Avast using ASWCLEAR.EXE.

Important: Do not run ASWCLEAR.EXE in Safe Mode if the Self-Defense Module is disabled.

Following these steps ensures that your system is completely cleared of previous Avast installations, avoiding conflicts and enabling a smooth migration to the cloud version.