All the Avast antivirus users need to upgrade to Avast 2014 first, then to Windows 8.1 according to a blog post on on Avast website. Avast! 2014 has Windows 8.1 certification which ensures that it meets compatibility standards and performs well on the Windows platform. Older versions of avast! Antivirus do not carry that certification, so if you update to Windows 8.1, it will disable avast!
Here’s how upgrade to Avast 2014:
- Open the avast! user interface and click on the Maintenance tab.
- Click Update Program
- The Update screen shows you the overall progress
- When it’s done, you will be asked to restart your computer. Click ‘Yes’ to reboot.
- Click ‘Continue’ to complete the upgrade.
After this, the latest version of avast! Antivirus 2014 is installed on your computer and then you can make the upgrade to Windows 8.1.