mjk that is not as silly as it sounds, if you have very old kit. I have some retail copies of Win 3.11 for workgroups. For a low end 80486 or higher end 80386 it will run very stable. Lower specs than that and you would have to use DOS.

I have seen an 80286 used to control a FAX machine and in the past, old 386s to control software licences (one step up from the dongle )

Of course you could never use it on the internet, as most ISPs won't support anything less than Win98SE these days.