ok , greek fonts .. easy!
FYI ure actually activating greek fontset , you're not using a greek font, ie greek should work with all fonts after you do this
winxp - go to control panel - activate the classic menu listing, then select regional and language options.
in there theres a "languages" tab
press "details" then add, and select greek with a standard keyboard, you can set a hotkey to switch between input languages now or a little EN -for english and EL for greek should pop up next to your taskbar for your selection i think the standard default switch key is left alt and shift at the same time.
note: do add tonous you need to press the ; button before u press a character when in greek. this will add the tono on top of the character you want. you should be able to add languages in all windows environments, its just that in WINXP it preinstalled as most things do in WINXP. im not too sure about the other operating systems, but im guessing its the exact same steps apart from the fact that you have to enter your installation disk in order for it to copy the needed files
note2. just because you have INPUT language as greek doesnt not mean that GREEK programs will display in greek, i think it becomes a little more complex when it comes to that , IE installing a greek version of windows or perhaps some programs (example winamp) will have language plugins.
Thats all!! any of you need a hand.. tough read the instruction and you should be fine