In Microsoft Word, you can insert Greek characters or even change Windows settings to add a Greek keyboard. To add a keyboard in Windows 8, press "Windows-X" and select "Control Panel." Under Clock, Language and Region, select "Change Input Methods." Click "Add a Language" and scroll down until you see Greek and select it. To switch easily between the two keyboards, use "Windows-Spacebar." Also note that now that you've enabled it, this Greek keyboard is available everywhere in Windows.
Accessing Breath Marks and Accents With the Symbols Menu
To insert a Greek character through the Symbols menu, select the "Insert" tab, click "Symbol," and then select "More Symbols... ." All the Greek letters with no markings, capital and lowercase, are available with "(Normal Text)" selected on the Font drop-down menu. Set the same Font drop-down menu to "Arial" and the Subset to "Greek Extended" for Greek characters with breath marks and accents.
Use Shortcut Commands to Insert Greek Characters
If you frequently use a particular Greek character in English documents or you want an easier way to type the Extended Greek characters, try committing a few character codes to memory. Typing the character's code followed by "Alt-X" inserts the character in your document. To find a character's code, go to the More Symbols screen. For the symbol selected, Word displays the code for that symbol next to the "Shortcut Key..." button. Remember to have the English keyboard enabled to type the code.