Windows 10: WIN 10 Pro let a Trojan in,why?

Windows 10 Pro ( 10.0.19041 Build 19041) Defender let in Trojan: Win32/Blutealifrn into my computer.
When selecting actions,Defender did not remove it or even attempt to remove it.
Why?

:)

 

Excel will not use Thunderbird to email spreadsheet on Windows 10 Pro

I was trying to keep it simple, she's not the sharpest knife in the drawer but kind natured.
If i could emulate what I can do thenwhen she gets twined up I can talk her step by step.

if we can't sort why Win 10 Excel won't see T-B as the main email client then we'll just have to go with your suggestion.

I should have said Win 10 pro 64 bit?

 

Rooted Malware, Virus, and Trojan Infection, Keylogger Trojan Malware

Hi,

Please click the link below and follow Stephen Boots' suggestion on how to remove Trojan virus on your computer:

• List of anti-malware product removal tools

Let us know if you need further assistance.

 

Wins 10 pro becoming wins 7 pro

I am using wins 10 pro, but during end user activation it shows wins 7 pro

Any suggestion?

**Post moved by the moderator to the appropriate forum category.**