Using Vista -- Error installing CD-Rom Game

In short, you won't sorry. The game was developed for DOS with the intent of it running in Windows 95-98 and had issues with Windows. I would not even bother.

From http://www.warfaresims.com/?page_id=363

"Harpoon II was the MS/DOS version of the simulator. It was first released in 1994 on six 3.5 inch floppy disks and contained the battleset Global Conflicts One. The Global Conflicts Two and Three, Cold War, Westpac, and Regional Conflicts One battlesets were later released as add-ons. The next version, Harpoon II Deluxe Multimedia Edition, an improved version released on CD-ROM, contained the three battlesets Global Conflicts One, Two and Three as well as many new video and audio clips. It also included a printed manual and a scenario editor which allowed you to build your own scenarios. The final version was Harpoon II Admiral’s Edition. This had all six previous battlesets plus a new one, Regional Conflicts Two. However, being a MS/DOS application, Harpoon II suffered from severe stability problems on Windows 95, 98, ME platforms and would not run at all in pure 32-bit operating systems like NT 4.0, Windows 2000 and Windows XP. Because of these shortcomings, Harpoon II was ported to Windows and renamed Harpoon3."