1. Uninstall Avast Antivirus using the Avast Uninstall Tool as described in the following article:
   • Using the Avast Uninstall Tool
2. Manually delete any remaining Avast folders in the following default locations:
   
   64 bit type Windows PC:
   • C:\Program Files (x86)\Avast Software or C:\Program Files (x86)\Alwil Software
   • C:\ProgramData\Avast Software or C:\ProgramData\Alwil Software
   32 bit type Windows PC:
   • C:\Program Files\Avast Software or C:\Program Files\Alwil Software
   • C:\ProgramData\Avast Software or C:\ProgramData\Alwil Software
   Depending on your system preferences, the folders referenced above could be hidden. To display hidden files and folders, refer to the following Microsoft article: Microsoft ▸ View hidden files and folders in Windows.
   Depending on your system preferences, the folders referenced above could be hidden. To display hidden files and folders, refer to the following Microsoft article: Microsoft ▸ View hidden files and folders in Windows.
3. Manually uninstall Avast Firewall Driver (or Avast Firewall NDIS Filter Driver) if it exists in the Properties of your Network connections, by following the steps below:
   1. In File ExplorerWindows Explorer, right-click Network in the left panel, and select Properties from the context menu to open the Network and Sharing Center.
   2. Click Change adapter settings in the left panel to open Network connections.
   3. Right-click one of your connection icons (for example, Local Area Connection) and select Properties from the context menu.
   4. Select Avast Firewall Driver and click Uninstall.
4. Reboot your computer and start Windows in Safe Mode by following the steps in the article below:
   • Restarting Microsoft Windows in Safe Mode
5. In Windows Safe Mode, search for and delete all files starting with aswNdis*.* if any exist in the following folder and its subfolders:
   • C:\Windows\System32\DriverStore
6. In Windows Safe Mode:
   1. Search for and delete all files starting with aswNdis*.* if any exist in the following folder and its subfolders:
      • C:\Windows\System32\DriverStore
   2. Search for and rename the file INFCACHE.1 to INFCACHE.1.BAK if it exists in the following default folders:
      • C:\Windows\System32\DriverStore
      • C:\Windows\Inf
7. If Windows (started in Safe Mode) refuses to delete any of these files, take ownership of the files by following the steps below:
   1. In File ExplorerWindows Explorer, right-click the file that you want to take ownership of, then select Properties from the context menu.
   2. Select the Security tab, then click Advanced.
   3. Next to Owner on the top, click Change (if prompted for permission by the User Account Control dialog, click Yes).
   4. Type Administrator or Administrators into the field entitled Enter the object name to select. Click Check Names to verify, then click OK repeatedly until all opened dialogs are closed.
   5. Below Name in the list, click Administrator or click the Administrators group, then click OK repeatedly until all opened dialogs are closed.
8. Clear all offline content and cookies from your web browser. For instructions, refer to your web browser's support article(s):
   • Google Chrome: Google Chrome Help ▸Clear browsing data | Clear, enable, and manage cookies in Chrome
   • Mozilla Firefox: Mozilla ▸ How to clear the Firefox cache | Clear cookies and site data in Firefox
   • Microsoft Edge: Microsoft ▸ View and delete browser history in Microsoft Edge
   • Internet Explorer: Microsoft ▸ How to delete the contents of the Temporary Internet Files folder | Delete and manage cookies
9. Temporarily turn off any firewall software. If you are using Microsoft Defender FirewallWindows Firewall, refer to the following Microsoft articleDell article:
   • Microsoft ▸ Turn Microsoft Defender Firewall on or off
   • Dell ▸ Turn Windows Firewall on or off in Windows 8
   • Microsoft ▸ I Need to Disable Windows Firewall
10. Download and install the latest version of Avast Antivirus. For detailed installation instructions, refer to the following article:
    • How do I install Avast Antivirus?
11. If you have a paid subscription, insert your activation code into your Avast Antivirus. For detailed instructions about how to activate your subscription, refer to the following article:
    • How do I activate Avast Premium Security?
12. If you don't have Avast Premium Security, turn on your firewall software. For more instructions, refer to the relevant vendor documentation. If you are using Microsoft Defender FirewallWindows Firewall, refer to the following Microsoft articleDell article:
    • Microsoft ▸ Turn Microsoft Defender Firewall on or off
    • Dell ▸ Turn Windows Firewall on or off in Windows 8
    • Microsoft ▸ Turn on your Windows Defender Firewall

All Avast Antivirus program component issues are now resolved.