This document shows which fonts on Win 7 have the ‘okina and kahakō characters used in Hawaiian and other Polynesian languages. You’ll find that only the following Windows 7 fonts have the ‘okina and all vowel-kahakō characters (at least in the standard install on our Dell):
Arial, Arial Unicode MS, Calibri, Cambria, Cambria Math, Consolas, Courier New, Lucida Sans Unicode, Meiryo, Meiryo UI, Microsoft Sans Serif, Segoe UI,Segoe UI Light, Segoe UI Semibold, Tahoma, and Times New Roman
Some others have some or all of the vowel-macron characters, but not all. Some fonts have none at all. This document is provided without warranty or guarantee, though if you find any errors I will be happy to correct it.