After many different error messages concerning X, rights and the wrong number of devices detected,etc,
I deleted Xauthority files as suggested in a post, did a chown on my account and tried drakconf several times.
Each time I test the graphics setup or validate it goes to black screen. Drakconf detects an older card than is installed, I've tried disabling all options, small resolutions and the nv and nouveau drivers.
Nothing works.
Help please, must I reinstall?

Mageia 6, KDE stock clean install

My first encounter with Linux was Mandrake/Mandriva many years ago...
It had all these Drake configurators, which were quite unstable.

So I moved on.

Ubuntu was getting good reviews (at that time).
Never used KDE, but I would suggest trials of Mint, Debian or LMDE.

I would say yes if your a newbie and it doesn't work ... try Ghost BSD or Ubuntu / Fedora linux'es.

xorg-server setup was (maybe is still) infamous for giving people the black screen - and some distro admins (ie ubuntu) accused the victims and close (prevented further discussion)

The problem there? People's keyboard (or moreso mouse) were not detected by xorg in a timely manner, xorg would give a black screen but xorg HAS A BYPASS for that (see xorg's documentation) that allows startup "without keybaord and mouse". When used it worked because xorg did detect them it just didn't detect them quickly enough before that "check", thus many many people were getting black screens - and many chose to go to win10 or macOS Sierra thinking linux were a bunch of liars.

personally i'd still like to hear why/how that major incident, which went on for years, all went down (noting X11R6-4.8.0 never had such a problem. i mean: they added the problem and didn't tell new users about it when asked. very strange.)

I'm not a newbie after more than 10 years, just a normal user willing to try to use and promote linux.
My sytem was working okay and I was flying the Flightgear simulator regularly with a little o/c on the cpu and agressive settings in the nvidia config utility.

There are certainly bad things (parameters, drivers) that must be eradicated so as to configure correctly my card and monitor, that's my challenge but I know I'need help.

Anyone know how to purge and reinstall all X11 and NVIDIA files in a console using urpm or dnf?

Thanks all, I've reinstalled with Gnome, looks okay for now.