Really it depends on the game. For some games like DOSBox games you can (apparently) get the appropriate files and run them on original hardware; others have fixes that might basically be permanent.

If you're trying to run games on original hardware I imagine your best bet is to just find the original releases, however you go about it (Amazon, eBay, "elsewhere" if you really have to etc.)

This would be solved by providing the original media....

See these threads:
https://www.vogons.org/viewtopic.php?f=7&t=48490&hilit=GOG+digital
https://www.vogons.org/viewtopic.php?f=5&t=57100

so we can conclude that, gog does not provide compatibility with original system requirements and there might be ways to play some of the games on an old pc.

thanks for the replies.

Well, the intention of GoG always was, to make older games working on modern computers.

Don't all the old games on old hardware require "please insert disk" crap in order to run?

Apart from the above, i would say it is a very good reason to keep an old computer.... that and one day when someone finally manages a virus that kills modern OS, chances are it probably wont affect very old computers!

You would of course then need to keep spares of all the hardware, cables and such like as most is not made any more. Not very efficient in any sense. A better option would be to have multiple new computers with dual boot or virtual machines. A Pi for instance should be able to run most old games and doesn’t require old hardware.
Nobody is going to bother wasting their time writing an OS killing virus, between M$ doing their hardest to break it each (continuous) update and their being no real reward, that’s unlikely. What is more likely is that someone will create an OS lookalike which is only there to harvest all your data...a quick search reveals ChromeOS, too late!

Anyways, best thing you can do for any computer is to remove the Ethernet cable, that solves virtually every computer problem.

Except the main problem. The user... :p

If we could unplug the user, then all computer problems would be solved... :D

Edit: Removed unnecessary original quote...

Depends on what os you are using and the game. I pretty much have windows xp and still most of the games work on my pc that previously worked on win xp, sometimes if the system requirements are higher, it could be that GOG didn't have an older pc to test with it and made them higher in the minimum system requirements.
I just check other places for system requirements then like steam or systemrequirementslab or gamesystemrequirements.
But yes some games would not work on win xp i heard fallout 3 is one except if you get a special patch for it.

So just let’s play videos on YouTube?

Yea, that must be true because there are no humans with the motivation or the means to want to do harm to the free world in that fashion.

Amazing how true that is! If only to prevent windows frag your computer updates, then its worth it!

I used to keep my gaming computer disconnected permanently, since i dont play online games, it was fine. Never had any issue with it.

These days with most of my games on Steam and GOG, some internet connection is unavoidable.... ironically, my computer hates ethernet devices. I would buy one brand of ethernet device, have issues with it, then buy a different brand, have issues with that then buy another brand.... finally better, but still occasionally does funny things.... like if i am in a game and funny stuff starts happening, all i have to do is reach over and unplug the ethernet device and suddenly the game runs normally again.... its not even an online game!!!!

Yes. (And Yes, but this does not change the answer to the first part of your two part question, which is still Yes.)

Yes?

What's an "ethernet device"?

It's where the CAT goes to play.