what ever you intend to do , knoppix on a stick is useful .
English iso is here :
http://mirrors.sonic.net/knoppix/knoppix-dvd/KNOPPIX_V8.6-2019-08-08-EN.iso
i think you said you had a spare laptop ,so i'm only interested at this stage of you using the laptop to get knoppix onto a stick and that you can boot that usb from the laptop to prove it works. if you an do that then that usb with knoppix will be a tool that any of us on here including mods might ask you to make use of.
as for the way of getting it onto a stick try this:
Optimzation process for ubuntu/deepin/uos/kylin/Manjaro/CentOS7 Specical process for some USB drive SHA1: ventoy-1.0.08b1-windows.zip: 675e8da165da10c58662a01623131d132ac5a70c ventoy-1.0.08b1-lin...
github.com
choose either Windows or linux. So this is where i would like you to be Maybe tomorrow. You will have knoppix iso on Desktop of laptop and you will have the appropriate ventoy on Desktop as well. Lets look at this soley as getting something useful onto a USb stick, a side project as it were and thats as far as it goes. So that way it does not interefre with any other advice you are getting .I'm sure nobody is going to argue against having one spare usb with knoppix.
Ventoy will not give you persistence with knoppix but we don't need it
I'll keep my Desktop computer to hand (the same machine that's experiencing all the problems), but also make use of my Laptop which currently still has Windows 7 on it due to not having enough time to complete going through and backing up a backlog of files including photos on the laptop, so I will convert that computer to Linux asap.
In the meantime, as with other members, I am following your directions and will report back with my findings as soon as I can update you after my new USB sticks arrive, including with Windows.
Further attempts to download MX 19.1 onto my USB stick have failed, due to my desktop computer often automatically shutting down or restarting during downloads, thus ceasing them, eg MX and Knoppix.
However, another avenue I will explore, which may or may not amount to anything is to place my MX 17 USB stick into the Laptop (which is free from hardware errors). It's slower than my desktop and would need the Screensaver turned off for longer (so it doesn't revert eventually to the Log In screen which cancels downloads), but it works fine, and if all works out, I could download MX 19.1 onto the laptop, transfer it to a brand new USB stick (as before, per Wizard From Oz's DD installation method instructions who confirmed I'd followed directions correctly).
In turn, if the Laptop successfully gets MX 19.1 installed onto a new USB stick, it will be free of the February download with GRUB errors (which only relate to This computer), I can then return That stick to This computer, and provided the hardware faults blocking me direct access to my hard drive don't prevent MX 17 being overwritten, I should be able to use the MX 19.1 "Install" function from the USB stick onto my hard drive.
I can't guarantee this at present, as it depends on how things progress on the Laptop, but there's a chance this extra step on the Laptop will enable me to, finally, have MX 19.1 on This computer, and without any unwanted GRUB errors.
The above could also be applied initially on my laptop to Knoppix, any other program you've recommended, as if they can be transferred to a USB stick on That computer, the chances are very high, the same sticks will work fine on This computer, allowing installation (where installation is relevant, such as MX 19.1).
As I don't have enough USB sticks at present, I'll await deliveries of them so I can have a brand new one for MX 19.1 plus other ones for Knoppix and Ventoy.
It sounds promising that these programs will enable me to regain access to my hard drive (I hope so), and if even if not all faults can be fixed, if some can be fixed, this will increase my computer's functionality.