Flash Player has reached it's End Of Life, and is no longer available for download. We strongly advise against finding old Flash Player versions from third-party sites, as they could contain malware.
Safari, Chrome and Firefox have all dropped support for browser plug-ins at this point. IE and Edge will follow suit soon. It's difficult to find a current browser that will run Flash at this point. It's time to move on.
See the original announcement from 2017 for background and links to corresponding browser roadmaps:
https://theblog.adobe.com/adobe-flash-update/
Here's the consumer FAQ:
https://www.adobe.com/products/flashplayer/end-of-life.html
Here's the enterprise FAQ, which has some options for organizations that have legacy Flash dependencies that they need to keep running:
https://www.adobe.com/products/flashplayer/enterprise-end-of-life.html
We strongly encourage you to uninstall Flash Player at this point. For your convenience, links to the uninstallers
follow.
Uninstall Flash Player - Windows:
https://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html
Uninstall Flash Player - Mac:
https://helpx.adobe.com/flash-player/kb/uninstall-flash-player-mac-os.html
Microsoft Update for Removal of Flash Player for IE and Edge on Windows 8 and higher
https://support.microsoft.com/en-us/help/4577586/update-for-removal-of-adobe-flash-player
There's not enough context to answer your "why is it working" question. Are you on Windows 10? If so, it's probably because the built-in ActiveX Flash Player for IE and Edge (which is distributed by Microsoft, not Adobe) is still installed. The Windows Update patch I linked above will remove it. This patch will eventually become mandatory and will get applied automatically, but you can run it now if you want.
Long story short, it's time to find a solution that doesn't depend on Flash. I didn't build your language CD-ROMs, so I can't tell you whether or not Flash Player is totally mandatory, but my guess is that they will break once you uninstall Flash.
If money is an issue, one option would be to build a virtual machine (i.e. with VirtualBox/VMWare) with old software and use it just for the CD-ROMs. Turn off updates and keep it disconnected from the Internet. That's beyond the scope of what we're going to help with here, but you should be able to figure it out with a few google searches.