Money 99 is known to work with Windows 10. What troubleshooting steps did you try? The first step would be to uninstall Money 99, reboot then reinstall.
Upgrades to Windows, particularly to long since installed and multiply upgraded versions, can leave the latest upgraded version proving problematic. The remedy is to clean install the latest Windows version.
The second post in this forum gives links to later versions than Money 99. Choose the appropriate regional version for where you are.