    # CStruct Examples
    require 'windows/system_info'
    require 'win32struct'
    include Windows::SystemInfo

    # OSVERSIONINFOEXA in VC6 's SDK
    #typedef struct _OSVERSIONINFOEXA {
    #    DWORD dwOSVersionInfoSize;
    #    DWORD dwMajorVersion;
    #    DWORD dwMinorVersion;
    #    DWORD dwBuildNumber;
    #    DWORD dwPlatformId;
    #    CHAR   szCSDVersion[ 128 ];     // Maintenance string for PSS usage
    #    WORD wServicePackMajor;
    #    WORD wServicePackMinor;
    #    WORD wReserved[2];
    #} OSVERSIONINFOEXA;

    class OSVERSIONINFOEXA < Win32Struct
        DWORD :dwOSVersionInfoSize
        DWORD :dwMajorVersion
        DWORD :dwMinorVersion
        DWORD :dwBuildNumber
        DWORD :dwPlatformId
        CHAR  :szCSDVersion,[ 128 ]
        WORD  :wServicePackMajor
        WORD  :wServicePackMinor
        WORD  :wReserved,[2]
    end

    ver_info_ex = OSVERSIONINFOEXA.new do |st|
            st.dwOSVersionInfoSize = OSVERSIONINFOEXA.__size__  # __size__ is an alias for method 'size'
    end

    #ANSI Version: GetVersionExA
    GetVersionExA(ver_info_ex.__data__) # __data__ is an alias for method 'data'

    puts "<OS Version Infomation>"
    puts "Major Version:#{ver_info_ex.dwMajorVersion}"
    puts "Minor Version:#{ver_info_ex.dwMinorVersion}"
    puts "Build Number:#{ver_info_ex.dwBuildNumber}"
    puts "Platform Id:#{ver_info_ex.dwPlatformId}"
    puts "CSD Version:#{ver_info_ex.szCSDVersion.to_cstr}"                 # to_cstr return a string(C Style)
    puts "ServicePack Major:#{ver_info_ex.wServicePackMajor}"
    puts "ServicePack Minor:#{ver_info_ex.wServicePackMinor}"