Currently there are problems with Avira Antivirus and the Microsoft update KB4493467. This can cause the computer on Windows 7 and Windows 10 to slow down considerably and logon is no longer possible. Microsoft has currently stopped the distribution of the update for computers with Avira Antivirus and other antivirus solutions.
More detailed information can be found in the following Microsoft KB article:
https://support.microsoft.com/en-gb/hel ... -kb4493467
As soon as we have more information, we will inform you further here.