Maintaining an install of consumer legacy software

Let's say you have some consumer legacy software (LS) installed on an old operating system. You want to preserve the legacy software.

The options that come to mind are:
1) have the LS as a virtual machine of the old operating system on a modern computer. Move this VM as you upgrade your computer. The VM is kept in offline mode.
2) keep the LS on the old hardware. Sometimes move to newer hardware when you don't want to push your luck more with the hardware failing. Maybe find quality old hardware that will last?

Something to "add in" with either of the above approaches:
try to move the legacy software to progressively newer operating systems. Besides getting feedback from others that have tried with said software, what other guardrails/predictive mechanisms do you have? Maybe 32 bit software has/will stop being supported by modern operating systems. What is the level of risk that it "looks ok" but has quiet problems/ bugs?

LS could require connecting to a server during install. If that is the case, you would have to lean more towards the VM option.

What are some other considerations/ strategies?

I am not thinking in terms of legacy software that uses really old hardware, like interfacing with a serial or parallel port connected device.

Here is also an article that I found on the subject but is probably more focused on business software:
https://www.techrepublic.com/article/8-strategies-to-keep-legacy-systems-running/

We have some air-gapped computers that run test equipment at work that I have upgrading over time. Surprisingly even though the Windows XP era "legacy software" doesn't officially support Windows 11, I have had no difficulty installing and running it.
Likely, the reason this likely works is that the software connects to the test equipment over the network and Windows 11 still supports the legacy IIS and FTP networking from years ago.

I suppose if that didn't work, an older OS in a VM on modern hardware could work but that starts to get harder to support from both an end user perspective and systems support.

grim4593 said:

We have some air-gapped computers that run test equipment at work that I have upgrading over time. Surprisingly even though the Windows XP era "legacy software" doesn't officially support Windows 11, I have had no difficulty installing and running it.

Click to expand...

Good point. That is the 3rd choice.
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My main experience with virtual machines (VMs) is 6+ years of Virtualbox Windows VMs and GNU/Linux VMs.
1) Seems less reliable because VMs sometimes fails to boot. But then next time the VM will boot ok.
2) Sometimes window sizing has problems. For example, the window size when not maximized, slowly shrinks.
3) Accidentally booted a Windows VM after I removed a RAM chip. So, the VM was trying to use 80%+ of the memory. The host operating system had a full GUI/ was not light weight. It errored. Next time that I booted it, Windows was sounding a lot of alarm bells. I clicked through on 3 things and it loaded the Windows desktop GUI normally. User error but wouldn't have happened on bare metal (means not a VM).
4) One time moving a virtual machine to a new install did not work as I wanted. I copied the folders over and pointed the new install to that folder. Gave an error.
I am sure that some of this wouldn't have happened if I was more of an IT wiz.