Avast Antivirus 2015 Compatibility Issues with Win10

Just make sure you are running the latest version of Avast before trying any of the solutions below.

Solution #1.1 – Boot into Windows Safe Mode

If you are lucky the only thing you need to do is boot into Windows Safe Mode and then restart to the regular mode. If you are not sure how to do it, follow the instructions below:

• 1. Open Windows Run dialog by simultaneously pressing Windows key on your keyboard and ‘R’

  2. Enter ‘msconfig’ into Windows Run dialog and confirm

  3. System Configuration dialog will open. Go to ‘Boot’ and tick the option ‘Safe boot’

  4. Confirm and restart you computer

  5. Once you are in the Safe Mode just restart again into regular mode and the critical error with Start menu and Cortana should be gone

Alternatively you can boot into Safe Mode using the Advanced start-up:

• 1. Go to Power in the Windows Start menu, hold ‘Shift’ and click on ‘Restart’. This also works on the Sign-in window

  2. Your computer should reboot and display a Recovery options. Go to ‘Troubleshoot’ » ‘Advanced options’ » ‘Startup Settings’ » ‘Restart’

  3. Windows will reboot and the Startup Settings should display. Select Safe Mode by pressing F4 key on your keyboard

  4. Once you are in the Safe Mode just restart again into regular mode and the critical error with Start menu and Cortana should be gone

Solution #1.2 – Add new user account to Windows

Another solution which helped some users is creating a new local user account in Windows. If you are not sure how to do it, follow the instructions below:

• 1. Right-click on the Start menu icon and select ‘Command Prompt (Admin)’

  2. Enter ‘net user [username] [password] /add’ where username and password is the name and password of the new account. For example ‘net user Paul P4ssw0rd! /add’

Alternatively you can create a new user from the Control Panel:

• 1. Open Windows Run dialog by simultaneously pressing Windows key on your keyboard and ‘R’

  2. Enter ‘control userpasswords2’ into Windows Run dialog and confirm

  3. User Accounts window will open. Click on ‘Add…’

  4. Sign-in window will open. Click on ‘Sign in without a Microsoft account’ at the bottom of the screen

  5. Add a user window will open. Click on ‘Local account’ at the bottom of the screen

  6. Enter the user details for the new account, click on ‘Next’ and ‘Finish’

Solution #1.3 – Run the System File Checker tool to repair corrupted system files

You can try to repair the corrupted or missing system files using the Windows tool called System File Checker or SFC. It’s quite simple and apparently worked for lots of users:

• 1. Right-click on the Start menu icon and select ‘Command Prompt (Admin)’

  2. Type down ‘sfc /scannow’ and hit ‘Enter’ and wait after it finishes

  3. Restart your computer the Start menu and Cortana should be working again

Issue #2 – Avast SecureDNS can’t run on this network

Recently many of the Avast users have reported the issue with Avast SecureDNS on the official forum. SecureDNS is premium feature which protects you from phishing attacks using fake DNS servers. It is available only in the paid products Avast Pro Antivirus, Avast Internet Security and Avast Premier.

When this issue happens Avast will display a message ‘SecureDNS can’t run on this network’ in the status monitor. Although it will stay in the ‘green’ state like on the screenshot below.

Solution #2.1 – There is no solution at the moment

So far there is no available solution, but Avast is aware about this issue. Also you don’t need to worry about your security, it doesn’t have any impact on Avast detection.

Additional Notes

Although we have used Avast Free Antivirus 2015 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.

We have also a similar guide for compatibility issues on Windows 8 / 8.1.

If you are having any different problems with Avast Antivirus and Windows 10, just let us know in the comments below. Same if the described solutions and fixes didn’t work for you.