Leo: Well, if you want a legitimate copy, your best bet is probably eBay.
Patrick: What are you wanting to do with it?
Caller: I need it to run Windows 1.0 or Windows 3.1.
Leo: Oh, well in that case you'll need an older version of DOS, like DOS 2 or so.
Patrick: I think there's a website you can get older versions of DOS from, it's [insert name of website which I forgot and is irrelevant].
Caller: I tried that, it doesn't work right on my machine.
Patrick: Yeah, you might actually need to go to a garage sale or something and pick up an old 486 to get that to work properly.
Caller: When I installed DOS 2 on my machine it just made this horrible painful screeching sound.
Patrick: What kind of machine are you trying to install it on?
Caller: a MAC.