Computer Tutorial

The internet detective:-

                                                        We recommend this method as the starting point when trying to troubleshoot any Windows compatibility issues. The first thing to check is with the original publisher or author of the software. Download any patches or updates from the publisher or developers website if possible and then try again.

If the publisher is no longer in business, then perhaps there was a patch published before they disappeared. Sites like Fileplanet for example, host patches for older games.
Finally, many old cult video games from decades ago have been released into the public domain. Some games have even had their source code (programming code) released to the public. Games like this are often maintained and updated by enthusiasts long after the original developers and publishers have abandoned them.
If the software you are trying to run is a productivity application, perhaps there is a compatible product that will open the data files/documents that the old application produced? Again, you'll need to sleuth your way around the internet to find