See http://msdn.microsoft.com/en-us/library ... 85%29.aspx for list of encodings supported by MS Windows.Also i have come across greek subs which were useless regardless that setting, text was always displayed as a bunch of weird characters, or just a line of questionmarks. In that case, I just gave up.
Apart from Unicode, Greek can be ISO/IEC 8859-7:2003 and Windows codepage (ANSI) 1253, but also DOS OEM 737, DOS OEM 869, IBM EBCDIC 423, IBM EBCDIC 875, MAC OS Greek, and even Greek national standard ELOT 928...
You can open the sub file with MS word, where you can see the rendering with various proposed encodings at opening, and select a different encoding when saved (except if the file is UTF-8, as this is the only encoding which can be 100% determined by heuristics).