Use GetLocaleInfo function with LOCALE_SDECIMAL parameter.
procedure TForm1.Button1Click(Sender: TObject); var MyDecimal: PChar; begin MyDecimal:=StrAlloc(10); GetLocaleInfo( LOCALE_SYSTEM_DEFAULT, LOCALE_SDECIMAL, MyDecimal, 10); Label1.Caption:='System decimal is - "'+MyDecimal+'"'; end;