Check out the HRI's Greek font page, or e-mail them.
You may have to change your web browser so that when the language is Greek (or ISO-8859-7), to use your Greek font. These pages all are marked as being in the Greek (ISO-8859-7) character set, and an intelligent browser will notice this and change the font automatically, if you've told it which font to use for Greek. Mine, unfortunately, does not -- I have to tell it "This page is in Greek". However, it kind of knows; as soon as I tell it a language (even if I say the page is in Russian or Turkish), it switches to Greek because of the code in the header, and keeps the Greek font even when I switch back to "Western" later. So you may have to switch the language code back and forth. In Netscape Communicator 4.x, click on View|Code (or something like that -- I have a German Navigator); with Microsoft's Internet Explorer 3.x, click on the flags in the bottom right-hand corner. (Mail me to tell me how it works on your system, so I can include it here.)
If your browser has it right, the next line will be in Greek:
Αυτή η γραμμή είναι γραμμένη στα ελληνικά
(It says: this line is written in Greek.)
Note for those interested: I believe ISO-8859-7 is also called Latin-7. It is nearly the same as the Windows Greek code page (I think that has the number 1253), except for the accented capital alpha (go figure).