Greek Fonts Dont work in Office but work in Windows

I have a problem for a long time now and I would be grateful if
someone knows any solution.
I have installed the Greek fonts in Windows XP and I can see for
example filenames & directories in Greek, write documents in Greek
etc.
But sometimes some programs do not display letters in Greek but in
funny characters.
One of them was winzip which could not keep the original Greek
filenames & directories.

More importantly Outlook has quite often the same problem. When I try
to create a new contact for example, I cut and paste Greek names into
the contact name & address field. The pasted text is not the original
but again funny characters. I have found that if I paste the copied
greek text in the notes field of the contact area (big empty box where
one could write comments) then the greek text is pasted fine. If I
then copy that pasted text from the notes field into the name field of
the contact it is pasted OK with out funny characters.

What is the problem?