!macro customInit
    Var /GLOBAL WIN_VERSION
    Var /GLOBAL ARCH
    ClearErrors
        ReadRegStr $WIN_VERSION HKLM "Software\Microsoft\Windows NT\CurrentVersion" "CurrentBuild"
        ReadRegStr $ARCH HKLM "SYSTEM\CurrentControlSet\Control\Session Manager\Environment" "PROCESSOR_ARCHITECTURE"
        SetOutPath "$TEMP\your_app_name"
        SetOverwrite on
        ${if} $WIN_VERSION < 7600
            MessageBox MB_OK "The installation cannot continue as the operating system is not supported by Desktop Application."
            Abort
        ${elseif} $WIN_VERSION == 7600
            MessageBox MB_OK "Windows 7 Service Pack 1 required. You will be directed to download Windows 7 Service Pack 1 now. Please install it manually before you proceed."
            ${if} $ARCH == "x86"
                ExecShell "open" "https:://path/to/your/cdn/windows6.1-KB976932-x86.exe"
            ${elseif} $ARCH == "AMD64"
                ExecShell "open" "https:://path/to/your/cdn/windows6.1-KB976932-x64.exe"
            ${else}
                ExecShell "open" "https:://path/to/your/cdn/windows6.1-KB976932-ia64.exe"
            ${endIf}
            Abort
        ${elseif} $WIN_VERSION == 7601
            ExpandEnvStrings $1 %COMSPEC%
            ExecShellWait "" "$1" "/c $SysDir\systeminfo.exe | findstr KB4019990 > $TEMP\version" SW_HIDE
            FileOpen $2 $TEMP\version r
            FileRead $2 $3
            FileClose $2
            Delete $TEMP\version
            ${if} $3 == ""
                MessageBox MB_OK "Patch KB4019990 required. Will install it now."
                ${if} $ARCH == "x86"
                    File "..\..\..\..\statics\patches\Windows6.1-KB4019990-x86.msu"
                    ExecShellWait "open" "$TEMP\your_app_name\Windows6.1-KB4019990-x86.msu"
                ${elseif} $ARCH == "AMD64"
                    File "..\..\..\..\statics\patches\Windows6.1-KB4019990-x64.msu"
                    ExecShellWait "open" "$TEMP\your_app_name\Windows6.1-KB4019990-x64.msu"
                ${endIf}
                Goto done
            ${else}
                Goto done
            ${endif}
        ${elseif} $WIN_VERSION == 9200
            ExpandEnvStrings $1 %COMSPEC%
            ExecShellWait "" "$1" "/c $SysDir\systeminfo.exe | findstr KB4019990 > $TEMP\version" SW_HIDE
            FileOpen $2 $TEMP\version r
            FileRead $2 $3
            FileClose $2
            Delete $TEMP\version
            ${if} $3 == ""    
                ${if} $ARCH == "AMD64"
                    MessageBox MB_OK "Patch KB4019990 required. Will install it now."
                    File "..\..\..\..\statics\patches\Windows8-RT-KB4019990-x64.msu"
                    ExecShellWait "open" "$TEMP\your_app_name\Windows8-RT-KB4019990-x64.msu"                  
                ${endIf}
                Goto done
            ${else}
                Goto done
            ${endif}
        ${else}
            Goto done
        ${endif}
    done:
        RMDir /r "$TEMP\your_app_name"
!macroend