Incidentally I used Glary Utilities to uninstall the Dell App so it'd also sort out any remnants. I can't however reinstall to then remove with the uninstaller, so am stuck in a continual loop it seems.

This shows my prog in Cntrl Panel/ task mgr.

Trying to install Dell Command Update or Dell Update generates same fail message

Try installing an older version such as 4.0.0 ( Nov 5. 2020) - see link below) to see if it will install on the computer

<ADMIN NOTE: Broken link has been removed from this post by Dell>

Also, in the latest version (4.1.0), you read the Important Information listed in the driver details?

<ADMIN NOTE: Broken link has been removed from this post by Dell>

Edit / Important Information:

This version of Dell Command Update (DCU) now includes a Command Line Interface. DCU 2.X is upgradable to this version.

Dell Command Update requires Microsoft.NET Framework 4.6.1 (or later) to be installed on the system

Tried "V4", but unfortunately get same error/ doesn't install.

Also checked on Net Framework, reinstalled, but I get pop up saying it's already installed.

To anyone having the same problem, for me, a different file worked: 
Dell-Update-Alienware-Update-Application-for-Windows10_06J74_WIN_4.2.0_A00.EXE

To download from the official Dell drivers section