Officially Avast Antivirus 2015 is compatible with both Windows 8 and Windows 8.1. However, some users may have issues with running avast! on the latest Windows. This article covers the most known ones, as well as solutions for fixing them.
So far, this article covers four issues – #1 Action Center Pop-ups, #2 Blank/Black Screen, #3 Impossible Avast Uninstall, and #4 ‘Process Trust’ Error during the installation.
General advise to avoid any compatibility issues between Windows and Avast antivirus is to keep both of them updated to the latest version.
According to Windows Compatibility Center, Avast antivirus 2014 is compatible. Based on 1,700 out of 1,840 users. If you’re one of the unlucky ones, we hope this article will help you to fix your problems. Listing for Avast 2015 is yet not available.
According to Windows Compatibility Center Avast Antivirus 2014 (version 9) is Fully Compatible with Windows 8 and 8.1
Issue #1 – Windows Action Center Says Avast Antivirus is Turned Off
Apparently, this seems to be a very frequent issue. Windows 8 or 8.1 Action Center displays one of the following messages: ‘Check virus protection (important),’ ‘Windows Defender and Avast Antivirus are both turned off,’ or ‘Windows did not find an antivirus program’. Fortunately, fixing this issue is very easy.
Windows Action Center Messages Saying Avast Antivirus is Turned Off
Solution #1.1 – Just turn off (pause) your Avast antivirus for 10 minutes, then re-enable it:
- Find the orange Avast Antivirus icon in the system tray (usually it is hidden, so you need to click on the top arrow).
- Right click on it and go to ‘Avast shields control’, select ‘Disable for 10 minutes’, and confirm.
- Do the same to turn Avast back on by selecting ‘Enable all shields.’
Solution #1.2 – Let Windows Action Center to turn on and update Avast antivirus:
- Go to Windows Action Center by clicking on the ‘Open Action Center’ link or the pop-up message.
- Select ‘Turn on and update Avast Antivirus’ and Windows should start automatically updating your Avast Antivirus into the latest version.
Solution #1.3 – Reset Windows Action Center repository following these steps:
- Open the Command Prompt as Administrator (move the mouse to the bottom-left corner, wait until the box appears, right-click on it, and select Command Prompt (Admin)).
- In the Command Prompt type ‘winmgmt /verifyrepository’ and press Enter.
- If you get ‘WMI repository is consistent -no problems detected,’ type ‘winmgmt /resetrepository’ and press Enter.
- If you get ‘WMI repository is inconsistent -problems detected,’ type ‘winmgmt /salvagerepository’ and press Enter.
- If you get ‘WMI repository has been salvaged – WMI repository has been successfully rebuilt,’ continue to the last step.
- Restart your computer.
Issue #2 – Windows Won’t Start and Displays only a Blank/Black Screen
This issue is extremely annoying as it causes your Windows to not start and display a blank/black screen only. Users reported the issue started after they installed Avast Antivirus on their computer.
Solution #2.1 – In order to fix the blank/black screen issue follow these steps:
- Open the Task Manager by pressing ‘CTRL’ + ‘ALT’ + ‘Delete’ simultaneously, or ‘CTRL’ + ‘Shift’ + ‘Esc’ on your keyboard.
- When the Task Manager appears, click on ‘More details,’ then ‘Startup,’ right-click ‘Avast Antivirus,’then ‘Open file location.’
- In the opened folder, find a file called ‘AvastUI’ and double click on it.
- Now the Avast user interface should open, find the tab labeled ‘SECURITY’ » ‘ANTIVIRUS’ » ‘Behavior Shield,’ and find ‘Settings’ in the top-right corner of the ‘Behavior Shield’ window.
- When the Behavior Shield settings open, un-check the option ‘Monitor the system for unauthorized modifications.’
- Then go to the second settings tab, called ‘Trusted processes,’ add ‘C:\Windows\Explorer.exe,’ and ‘C:\Windows\ImmersiveControlPanel\SystemSettings.exe,’ and click ‘OK.’
- Restart your computer and Windows should now start smoothly without any issues.
Issue #3 – Windows Keeps Saying to Uninstall Avast Antivirus but It’s Already Uninstalled
In some cases, even the successful uninstallation of Avast Antivirus may not be recognized by Windows. If you are experiencing this problem, try one of these steps:
- Solution #3.1 – Uninstall Avast antivirus using the Avast Uninstall Utility.
- Solution #3.2 – Search for ‘avast’ using the Windows search and backup, then delete all ‘avast’ files found.
Issue #4 – ‘Process Trust’ Error During Avast Antivirus Installation
This issue happens if you are trying to install Avast Antivirus on your computer running Windows 8.1, and you get the ‘Process Trust’ fatal error pop-up message saying ‘Avast doesn’t trust Avast Installer,’ and the process was disabled. Usually, this happens when you have some other security software installed, typically Malwarebytes.
- Solution #4.1 – Disable/Uninstall any other security/anti-malware software you have installed on your computer. Then, try to run the installer again.
- Solution #4.2 – If you have Avast previously installed, uninstall it using the Avast Uninstall Utility.
Let us Know if Your Issue is Missing or the Solutions Didn’t Work
If you are having any different problems with Avast Antivirus and Windows 8 / 8.1, just let us know in the comments at the bottom of this page. Same if the described solutions and fixes didn’t work for you.
Although we have used Avast Free Antivirus 2016 screenshots in this article, these steps are also applicable for all Avast Antivirus solutions (i.e. also for Avast Pro Antivirus, Avast Internet Security, or Avast Premier) running the latest version available.
Steps are relevant for all Windows versions – Windows XP, Windows Vista, Windows 7, Windows 8, Windows 8.1 and Windows 10 (including Anniversary Update).