This happens in the world of CNC machines too. I used to run a two million dollar Mazak 300 Fabrigear that was made in 2008. When I started the machine up, Windows 98 booted up before starting the FANUC control program that actually ran the machine.
My friend's dad has a CNC machine that requires floppy disks to load the design patterns. He's worried that a mechanical failure of the disk drive will eventually be the end of it, rather than the machine itself being obsolete. It's been going strong for almost 40 years now.
It's reverse: you get a board that has a floppy interface on one side and a USB socket on the other. You plug in a USB drive and the board uses a file on the drive as the floppy disk, pretending to be a floppy Drive connected to the interface. It's a little less convenient because you have to deal with disk images but it works without moving parts.
It might be possible to buy an old floppy drive off ebay and switch out the broken one of that happens, as long as there are no proprietary connectors and such...
Ah yes, Compaq, the company that used non standard power supplies but with the standard wire coloring and connectors. I had several customers blow up their motherboards after buying standard replacement power supplies.
As long as it’s not connected to a network and is actually maintained, there’s nothing specifically wrong with Windows 98. Also just make sure the USB ports are shut.
It's amazing even for the cheaper CnC machines in other industries running on Dos or Win95, 98, XP. I use to have to maintain the hardware of these older PCs as the initial outlay to replace the machines was fairly high compared to stress and much lower cost of finding old hardware.
In the end with the modem equivalent CnC machines on the lower end we would only see minimal upgrades to the functions of the machines, versus the updates to the software. Let's me honest that would become obsolete yet again within a few years.