Windows 10: Error messages being received

I am currently running Windows10 Professional version 1903 - Build 18362.778

A number of times during the past week I have had a message appear on my desktop.
Can anyone tell me what it is please and is it anything I need to be concerned about or, is there anything that I need to do to stop it from appearing.

I have also had messages appear in the bottom right hand corner of my monitor. This message says that Windows defender has recognised virus threats and I need to take action. I've only remembered this because one just appeared after I logged-on just now. When i looked yesterday there were a number that were labelled as 'severe' and some as 'medium'. I seem to recall that I had the option to 'ignore' 'quarantine' or 'remove' them.
I didn't know what I was doing so I simply removed them. I recall that the word 'trojan' was mentioned at some point.

Is all of this any cause for concern and is action needed outside of me just 'removing' them?

Here is a shot of the first error that I mentioned above. I can only describe it as looking like a 'DOS' screen




Many thanks for any help that may be offered.

:)

 

Aquamark error message

I think I've received this error message with an gpu overclock that was too high, though it's been awhile since I've run aquamark.

 

Windows Update Error Message 0x80070543


Ya Ya Ya, there's over a hundred threads like this, ...

Anyway, started getting this error message a few days ago, and done a lot of searching on this error message, apparently it's not, uncommon.

In particular, the (currently) 4 updates that are being affected are:

• Update for Windows 10 Version 1511 (KB3173428) - Error 0x80070543
• Security Update for Windows 10 Version 1511 (KB3172729) - Error 0x80070543
• Security Update for Adobe Flash Player for Windows 10 Version 1511 (KB3174060) - Error 0x80070543
• Cumulative Update for Windows 10 Version 1511 (KB3176493) - Error 0x80070543

The actions I've taken to date are:

1. Uninstalled firewall program (comodo)
2. Uninstalled anti-virus (Avast)
3. Reset the windows update catalog on local machine.

So the above errors are with the above done.

What other steps should I be taking to resolve the issue?

Below is notations for when I actually add to this thread.

1. Attempted to use the troubleshooter, no dice.

 

the witcher demo

^ what they said will both work. i suggest updating directX, and in the future please try and list the exact error message... and i want a muffin.