It's a mess; you have to approach every title individually. I keep all my old games but the reality is that without people posting guides on reddit, i would stand very little chance making most of them work on my own.
Data Hoarder
We are digital librarians. Among us are represented the various reasons to keep data -- legal requirements, competitive requirements, uncertainty of permanence of cloud services, distaste for transmitting your data externally (e.g. government or corporate espionage), cultural and familial archivists, internet collapse preppers, and people who do it themselves so they're sure it's done right. Everyone has their reasons for curating the data they have decided to keep (either forever or For A Damn Long Time (tm) ). Along the way we have sought out like-minded individuals to exchange strategies, war stories, and cautionary tales of failures.
i would see if those games are on gog.com, if they are i would consider buying them if i were you, alot of old games need tweaks to get them to run (or run properly) on newer systems.
ISO them. You can always run them in an XP Virtual Machine etc.
I have Star Craft happily running in a VM on my Win10 machine here.