Recently, I was looking for a list of locales supported by Windows as well as the locale ID values and abbreviations for each of them. Fortunately, a friend pointed me at this location on MSDN:
Locale Identifier Constants and Strings - http://msdn2.microsoft.com/en-us/library/ms776260.aspx
This link includes a table of supported locales, what version of Windows each locale was introduced in, the hexadecimal locale identifier value (such as 0x0409 for US English), the locale name and abbreviation (such as en-US for US English).
The information in this table can be very useful if you are developing multi-lingual applications, so I wanted to link to it here to make it easier to find in the future.