flussonic.nsi

;!define VERSION "1.5.2"
; version is set via command line

Name    "Flussonic"       ; The name of the installation
OutFile "..\flussonic-${VERSION}.exe"   ; The name of the unistaller file to write
InstallDir "C:\Program Files\Flussonic"


!verbose 1
!define MUI_MANUALVERBOSE 1
!define MUI_PRODUCT "Flussonic"

!define TEMP $R0

;!include "MUI.nsh"
!include "EnvVarUpdate.nsh"
;!insertmacro MUI_PAGE_LICENSE "eula.txt"
;!insertmacro MUI_TEXT_LICENSE_TITLE "Read flussonic license please"


!include nsDialogs.nsh
!include LogicLib.nsh

;RequestExecutionLevel admin

Page directory
;Page license
Page custom GetLicense ValidateLicense
Page instfiles
XPStyle on
RequestExecutionLevel admin

!define UNINST_REG "Software\Microsoft\Windows\CurrentVersion\Uninstall\$(^Name)"
!define UNINST_EXE "FlussonicUninstall.exe"
!define SERVICE_PARAM "System\CurrentControlSet\Services\$(^Name)\Parameters"

Function .onInit
  InitPluginsDir
  File /oname=$PLUGINSDIR\win32-license.ini "win32-license.ini"
FunctionEnd

var Label
var Text
var License
Function GetLicense
  WriteRegStr HKCU "SOFTWARE\Flussonic" "installation" "going"
  ReadRegStr $License HKLM Software\Flussonic "license"
  ;WriteINIStr "$PLUGINSDIR\win32-license.ini" "Field 2" "Text" $0
  ;InstallOptions::dialog "$PLUGINSDIR\win32-license.ini"

  nsDialogs::Create 1018

  ${NSD_CreateLabel} 0 0 100% 12u "Your license key"
  Pop $Label

  ${NSD_CreateText} 0 13u 100% 15u "$License"
  Pop $Text

  nsDialogs::Show
FunctionEnd

Function ValidateLicense
  ${NSD_GetText} $Text $0

  ${If} $0 == ""
    MessageBox MB_OK "You need to enter license key"
    Abort
  ${Endif}

  WriteRegStr HKLM "SOFTWARE\Flussonic" "license" $0

  ;ReadINIStr $R0 "$PLUGINSDIR\win32-license.ini" "Field 1" "State"
  ;ReadRegStr $R0 HKLM "Software\Flussonic" "license"
  ;${If} $R0 == ""
  ;  ;WriteRegStr HKLM "Software\Flussonic" "license" "empty-license"
  ;  DetailPrint "No license in registry"
  ;${EndIf}
FunctionEnd

Section "Install"
  SetOutPath $INSTDIR

  WriteRegStr HKLM "SOFTWARE\Flussonic" "" $INSTDIR


  WriteUninstaller "$INSTDIR\uninstall.exe"
  WriteRegStr HKLM "${UNINST_REG}" "DisplayName" "Flussonic"
  WriteRegStr HKLM "${UNINST_REG}" "DisplayVersion" "${VERSION}"
  WriteRegStr HKLM "${UNINST_REG}" "InstallLocation" "$INSTDIR"
  WriteRegStr HKLM "${UNINST_REG}" "Published" "Flussonic"
  WriteRegStr HKLM "${UNINST_REG}" "UninstallString" "$INSTDIR\${UNINST_EXE}"
  WriteRegStr HKLM "${UNINST_REG}" "URLInfoAbout" "http://flussonic.com/"
  WriteRegDWORD HKLM "${UNINST_REG}" "NoModify" 1
  WriteRegDWORD HKLM "${UNINST_REG}" "NoRepair" 1

  ${EnvVarUpdate} $0 "PATH" "R" "HKLM" "C:\Program Files\erl7.2.1\bin"
  ${EnvVarUpdate} $0 "PATH" "R" "HKLM" "C:\Program Files\erl7.2.1\erts-7.2.1\bin"
  ${EnvVarUpdate} $0 "PATH" "A" "HKLM" "C:\Program Files\erl7.2.1\bin"
  ${EnvVarUpdate} $0 "PATH" "A" "HKLM" "C:\Program Files\erl7.2.1\erts-7.2.1\bin"

  ReadEnvStr $R0 "PATH"
  StrCpy $R0 "$R0;C:\Program Files\erl7.2.1\bin;C:\Program Files\erl7.2.1\erts-7.2.1\bin"
  System::Call 'Kernel32::SetEnvironmentVariableA(t, t) i("PATH", R0).r0'

  
  File /r ..\tmproot\opt\flussonic\*.*
  File /oname=run.bat run.bat
  File /oname=priv\flussonic.conf ..\deploy\sample\flussonic-win32.conf
  
;  WriteRegStr HKLM "${SERVICE_PARAM}" "Application" "$INSTDIR\Flussonic.exe"
;  WriteRegStr HKLM "${SERVICE_PARAM}" "AppParameters" ""
;  WriteRegStr HKLM "${SERVICE_PARAM}" "AppDirectory" "$INSTDIR"
  createShortCut "$SMPROGRAMS\FlussonicUninstall.lnk" "$INSTDIR\uninstall.exe"

  ExecWait 'erlsrv.exe add Flussonic -stop "erlang:halt(0)" -onfail restart -env "ERL_LIBS=apps;libs" -workdir "C:\Program Files\Flussonic" -sname flussonic -args "-boot start_sasl -pa apps\*\ebin -pa libs\*\ebin -s flussonic -sasl errlog_type error" -debugtype reuse' $0
  DetailPrint "Flussonic service returned $0"

  ExecWait 'erlsrv start Flussonic' $0
  DetailPrint "Flussonic starting: $0"

  ReadRegStr $R0 HKLM "Software\Flussonic" "license"
SectionEnd
 
; Set prompt text for uninstall window
UninstallText "This will uninstall Flussonic. Press 'Uninstall' to continue."
 
; Define steps to unistall everything installed.
Section "Uninstall"
  ExecWait 'erlsrv stop Flussonic'
  ExecWait 'erlsrv remove Flussonic'
  ${un.EnvVarUpdate} $0 "PATH" "R" "HKLM" "C:\Program Files\erl7.2.1\bin"
  ${un.EnvVarUpdate} $0 "PATH" "R" "HKLM" "C:\Program Files\erl7.2.1\erts-7.2.1\bin"
  DeleteRegKey HKLM "${UNINST_REG}"
  ;DeleteRegKey HKLM "System\CurrentControlSet\Services\$(^Name)"
  Delete "$INSTDIR\uninstall.exe"
  Delete "$SMPROGRAMS\FlussonicUninstall.lnk"
  DetailPrint "$(^Name) removing"
  RMDir /r /REBOOTOK $INSTDIR
SectionEnd
 
; eof

Hello, hardcoded PROGRAM_FILES path not canonical way, you should use predefined variables $PROGRAMFILES, $PROGRAMFILES32 or $PROGRAMFILES64.
For more info about that http://nsis.sourceforge.net/Reference/$PROGRAMFILES .
Of course, in 99% this path will be correct on target system, but if user changed it this script will be broken.