NSIS installer for 64-bit Windows

Here are some tips for creating (32-bit) NSIS installer which installs 64-bit application on 64-bit Windows.

There is no 64-bit NSIS Installer (yet) so only 32-bit version will be running on 64-bit host which means that 32-bit redirection will take place: by default its Installation Directory is "C:\Program Files (x86)" and it reads/writes only from HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node portion of the registry. This is not what we want so we need to enable access to native Win64 directories/registry for our Installer.

Our installer, as 32-bit application, will probably be used both for 32-bit and 64-bit installations. It therefore needs to be able to determine architecture of the CPU it runs on. x64 plug-in offers macro RunningX64 which returns true if installer is running on 64-bit Windows (under WoW64 emulation):

setup.nsi:

!include x64.nsh
...
${If} ${RunningX64}
   DetailPrint "Installer running on 64-bit host"
${EndIf}

Once we've detected 64-bit host, we need to:

• set "C:\Program Files" as Installation Directory - use $PROGRAMFILES64 instead of $PROGRAMFILES
• enable access to 64-bit registry - use SetRegView NSIS command

setup.nsi:

!include x64.nsh

;set initial value for $INSTDIR
InstallDir "$PROGRAMFILES\${MY_COMPANY}\${MY_APP}"
...
${If} ${RunningX64}
   DetailPrint "Installer running on 64-bit host"
   ; disable registry redirection (enable access to 64-bit portion of registry)
   SetRegView 64
   ; change install dir
   StrCpy $INSTDIR "$PROGRAMFILES64\${MY_COMPANY}\${MY_APP}"
${EndIf}

If installer needs to detect whether some 64-bit process is running, use FindProcDLL plug-in (there are couple of versions available but I found only this one - FindProcDLL_mod_by_hnedka.7z - working for me; please have a look at this forum thread). Download this archived file, unpack it and copy FindProcDLL.dll to your ..\NSIS\Plugins directory.

setup.nsi:

${If} ${RunningX64}
   FindProcDLL::FindProc "Some64BitProcess.exe"
   ${If} $R0 == 1
      DetailPrint "FindProcDLL::FindProc() returned 1 (process is running)"
   ${ElseIf} $R0 == 0
      DetailPrint "FindProcDLL::FindProc() returned 0 (process is not running)"
   ${Else}
      DetailPrint "FindProcDLL::FindProc() returned unexpected value"
   ${Endif}
${Else}
...