To run the software on another computer system that runs an operating system that does not support it, the best option for Henry would be:
A. running the software on a virtual version of the original operating system.
This approach allows him to create a virtual environment that mimics the original operating system, enabling the software to run as if it were on its native platform.
Options B and C involve modifying the hardware or upgrading the OS, which may not always be feasible or practical. Option D would require significant effort in rewriting the software, which might not be necessary if virtualization is a simpler solution.