According to Microsoft, users of some AVG and Avast antivirus software may experience issues when upgrading to the latest version of Windows 10. In fact, there is a compatibility issuethat is preventing users from making the upgrade.
Microsoft has blocked upgrades to versions 1909 and 1903 Windows for AVG users. As for Avast users, those running version 19.5.4444.567 or earlier will face the problem.
To prevent blocking, users should install an updated version of Avast or AVG software.
Avast and AVG support pages include the updated versions, as well as installation instructions.
Microsoft has now announced that it is blocking upgrades due to a compatibility issue for AVG and Avast. However, some users have reported that they have been unable to install version 1903 since August.

AVG's page states that the ban affects AVG Ultimate 19.5 (and earlier versions), AVG Internet Security 19.5 (and earlier versions), and AVG AntiVirus FREE 19.5 (and earlier versions). As for products , those affected are Avast Premium Security 19.5 (and earlier versions), Avast Premier 19.5 (and earlier versions), Avast Internet Security 19.5 (and earlier versions), and Avast Free Antivirus 19.5 (and earlier versions).
Microsoft has also blocked Windows 10 updates for versions 1903, 1909, and 1809 due to a compatibility issue with certain Qualcomm Wi-Fi drivers. To upgrade, users will first need to update the driver. Users will receive a messageinforming them of the need to update. If the update is completed, the block will be lifted and users will be able to install the newer version of Windows 10.
"Once you update your Qualcomm Wi-Fi adapter drivers, the block will be removed and you will be able to install the latest version of Windows 10," Microsoft notes.
