Update of Windows 10 doesn't work

I have disinstalled avast free without problems. When I try to install Windows 10 updates I get an error “Remove the app Avira because it is not compatible with Windows 10.”.
How can I do?
Thanks
Gianni

Presumably Avira (no connection to Avast) was on your system prior to Avast ?

There would appear to be some remnants of the old installation on your system that MS is finding.

See if this helps you.
How to Successfully Install Avast http://goo.gl/VLXde