Cosa vuol dire questo errore?

With all the problems you are having with Windows, your best option now will be to perform an in-place repair with the Windows 10 ISO

Please follow the steps, this is then just an update and your personal files, settings and installed software will not be affected.

Click this link:

https://www.microsoft.com/software-download/win...

to download the Media Creation Tool (Click on Download Tool Now), with that you can download the latest Windows 10 ISO (Select Create Installation Media for Another PC), then choose ISO, not USB

When the ISO file completes downloading

Disconnect from the Internet

Disconnect all external devices with the exception of a mouse or keyboard.

Temporarily disable any 3rd party Anti-virus you may have installed

Then, in Windows File Explorer, double click the ISO and then run Setup.exe and select the upgrade option.

this from avast anti rootkit software

udp flooding attack

wupdate not working

1

If you have installed that update, then your PC should be fully up to date, please provide a screenshot of the Windows Updates page in the Settings app.

2

Please provide a screenshot of that UDP FLOOD ATTACK you are referring to.