In the Start menu, find and select Control Panel. In the resulting window, double click the icon called "Regional and Language Options".
In the Regional and Language Options window, click on the tab at the top labeled 'Languages' and then click the Details... button.
In this window, you will find a list of all the languages currently enabled. Click the Add button to add a new language to the list.
In the Input language drop-down list, select Greek. In the field labeled Keyboard Layout/IME, select Greek Polytonic.
Click OK to close this window and then Apply in the underlying window. Again click OK to close this window.
In the bottom right hand corner of the screen, you should now see an icon similar to . Click this icon to see a list of the installed languages, and select the EL (Greek) icon.
Alt-Gr (right side) state:
Alt-Gr and Shift state:
Normal state & Spacebar:
Shift state & Spacebar:
Alt-Gr state & Spacebar:
Alt-Gr + Shift state & Spacebar