Print all std::locale names (Windows)

My program checks for uppercase letters in German language.

#include <iostream>
#include <boost/algorithm/string/classification.hpp>
#include <boost/locale.hpp>

using namespace std;

int main()
{
    locale::global(locale("Germany_german"));
    //locale::global(locale("de_DE.UTF-8")); //Also tried "de_DE.UTF-8", but does not work

    string str1 = "über";
    cout << boolalpha << any_of(str1.begin(), str1.end(), boost::algorithm::is_upper()) << endl;

    string str2 = "Ää";
    cout << boolalpha << any_of(str2.begin(), str2.end(), boost::algorithm::is_upper()) << endl;

    return 0;
}

program crashes with error on console

terminate called after throwing an instance of 'std::runtime_error'
  what():  locale::facet::_S_create_c_locale name not valid

I don't know what that exact locale string is, "de_DE.UTF-8" doesn't work as well.

Is there any way I can get exact locale name strings for all locales supported by OS. May be there is a list somewhere in header files, but I don't see anything <locale> header.