During installation of the Avira Firewall FWINST.EXE returned error 0x800F0203.
Usually this means the driver cache is corrupt.
In this case the installation of the Avira Firewall cannot be completed.
Remove the file “%WINDIR%\INF\INFCACHE.1” and restart your computer.
If the file “%WINDIR%\INF\INFCACHE.1” isn’t visible, enable the following option in “Windows Explorer”.
Start a change installation via Control Panel and try to reinstall the Avira FireWall.