add a USA locale for windows 7 server

Testing on a local windows 7 server outputted locale info as "C" on the server information shown in the admin header (ie showed no locale info at all).
The locales 'en_US', 'en_US.utf8', 'en' are not on this server, while  'English_United States.1252' is.
This shows up correctly in the header.
Maybe
1) the check if ($loc !== FALSE) echo ' - ' . $loc; needs expanding and
2) this locale should be added to the locale list as shown, as an example of needing different styles of locale definitions depending on the server flavour.