In Microsoft Word, a font called Symbol is used to display the common Greek alphabet characters. Symbol is also used to display other characters that are commonly used in the English language.
In addition to Microsoft Word's basic Greek font, there are numerous other Greek fonts available as free downloads. Some older Greek fonts are not recognized by newer systems and thus do not always display properly.
The Unicode fonts were developed in an effort to standardize all languages across computers worldwide. The first Unicode Greek fonts did not have the capacity to generate accented characters, but this flaw has been corrected.