Extract all files from the .iso image(s) into a directory ~ burn the dir ...

...which .iso files are you referring to?

And the resulting "burn" will be bootable? I thought there would be more to it then that. Years and years ago I somehow used Norton Utilities to make a bootable ms-dos cd. Don't ask me to repeat it. Me thought cds/dvds had something akin to a boot sector. And something was needed to write files to it properly. Something extra special.

The issue had come up more then once. The most recent instance is a set of Windows 7 restore disks for an HP computer. The case actually has 2 keys, 1 partially obscured. The 2nd sticker says "don't use other key "... uh can't anyway , and is specified for refurbs. Not exactly hopeful the key will work.

Which leads to a question - when exactly are keys stored in firmware. I had an old W7 restore disk from a different manufacturer. I tried installing it, and never askes for a key. Everything seemed fine until I noticed a 2x days to activate notification.

Are keys only present in Wimdows 10 computers?

kant explain wrote on 2023-09-19, 01:44:

Which leads to a question - when exactly are keys stored in firmware. I had an old W7 restore disk from a different manufacturer. I tried installing it, and never askes for a key. Everything seemed fine until I noticed a 2x days to activate notification.

Usually when they are OEM builds (Dell, HP, IBM..others, blabla)... for example I have an Aptiva Restore CD (from 1999) that is 'cracked' to work on any machine. That said, I never use them, and just install using the 'generic' media, not the custom restore install sets (but they can be handy for drivers)

Ventoy is an open source tool to create bootable USB drive for ISO/WIM/IMG/VHD(x)/EFI files.
With ventoy, you don't need to format the disk over and over, you just need to copy the ISO/WIM/IMG/VHD(x)/EFI files to the USB drive and boot them directly.

https://www.ventoy.net/en/index.html

I have used Ventoy to put ISOs of multiple different Linux distros on the same USB stick.

Embedded Windows keys in firmware started appearing in the late Win 7 period and it's almost all exclusively done that way these days. It's not just big OEMs either; for a while my company bought lots of kit from "Stone Computers" who largely used off the shelf Asus motherboards, and they had all the Windows keys injected into the firmware for those, too - no case stickers on those, either (that was 2016 ish).

Im sure there are ways to get to it from Windows, but from a Linux live cd you can run:

sudo cat /sys/firmware/acpi/tables/MSDM

Which will print out the key from firmware, if it has one.

kant explain wrote on 2023-09-19, 01:44:

Which leads to a question - when exactly are keys stored in firmware. I had an old W7 restore disk from a different manufacturer. I tried installing it, and never askes for a key. Everything seemed fine until I noticed a 2x days to activate notification.

Are keys only present in Wimdows 10 computers?

Dell put Windows XP keys in the firmware of their mid-2000s Pentium 4 systems.
It doesn't work with a generic retail CD though, it requires an install disc that was intended for those Dells. The one I acquired had I think 3 different versions of XP on it. I don't remember if I had to pick or if it auto-detects what license is on the motherboard.
There might be similar install discs for other brands of PCs.

zirkoni wrote on 2023-09-19, 05:17:

I have used Ventoy to put ISOs of multiple different Linux distros on the same USB stick.

I'm aware of tools like that. I don't think this is about booting multiple images. I assume only the first is bootable. The others may just contain ancillary/spurious packages, software, drivers etc.

kant explain wrote on 2023-09-19, 17:03:

I'm aware of tools like that. I don't think this is about booting multiple images. I assume only the first is bootable. The others may just contain ancillary/spurious packages, software, drivers etc.

It will boot into a Ventoy menu where you can select any live-CD image you have put on the USB stick. You can then start any of the live-CD environments and install the OS from the ISO.
But if want support for DOS/Windows 9x then I don't think Ventoy supports those, only modern Linux bootable ISOs, Windows 7+, etc