Any program that does not use only the very basic features of Windows, or any other operating system, will eventually stop working as the operating system is updated and upgraded. When that happens, either remain with the old operating system or change to
a newer, compatible program. However, there is no reason to think Money 2000 is now incompatible with any version of Windows.
First, uninstall, reboot then reinstall Money 2000.
You can upgrade, free, to the latest appropriate regional version of Money: see the second post in this forum.
Whatever Microsoft updates - if any - were installed since the last time you successfully ran Money 2000 will be in your update history and can be rolled back.
Updates might also be from your system supplier or security suite.
Note that one possibility is that your Windows installation has been corrupted somehow.