I’ve had this happen a few times in the past, and again, just a few days ago.
Customer had some labeling software that they purchased maybe 10 years ago.
Yes, they realise its very old, but it does the job, and they are happy.
The software is Teklynx labelview XLT+ V6.02 beta 1 R, connected to a Tec b-day443 label printer via a parallel port. Its all running on an old XP PC (although I wouldn’t be surprised if it was originally running on a windows 98 PC).
The customer was worried that the computer was about to die, and they didn’t have the original installation disks (they might have been floppies).
So I decide to take a look, and see if the software was old enough, that it could just be copied to a new PC without needing a re-install to alter the registry settings.
The software, including many years-worth of labels, was only 35Mb, so it looked promising.
After a quick copy to a newer XP PC, the labelview software started without a hitch, and was able to print to a newer USB laser printer.
For a bit of extra peace of mind, I also copied the software onto my office PC, and to my dropbox, so that there is little chance of losing it again.
So there you go: there are some advantages to using old software that is unaware of the windows registry.