This guide explains how to add custom functionality to your application’s Windows installer using NSIS (Nullsoft Scriptable Install System). We’ll use a real-world example of adding CUDA detection and installation during setup.

Overview

NSIS is a professional open-source system to create Windows installers. When building with electron-builder, NSIS is used as the default Windows installer. You can extend its functionality by:

  • Adding custom initialization code
  • Including additional NSIS plugins
  • Adding custom pages to the installer
  • Running checks before/during installation
  • Downloading and installing additional components

Basic Setup

First, configure your package.json to use custom NSIS scripts:

{
    "nsis": {
        "oneClick": false,
        "allowToChangeInstallationDirectory": true,
        "include": "build/installer.nsh",
        "perMachine": true,
        "allowElevation": true
    }
}

Adding Required NSIS Plugins

Add NSIS plugin packages as devDependencies in package.json:

{
    "devDependencies": {
        "nsisextra": "^1.0.0",
        "nsis-wmi": "^1.0.0",
        "nsis-inet-plugin": "^1.0.1"
    }
}

Creating Custom NSIS Scripts

Create a file named installer.nsh in your build directory. This file will contain your custom NSIS code.

Basic structure of installer.nsh:

!macro customInit
    ; Your initialization code here
    Function MyCustomFunction
        ; Function code
    FunctionEnd

    Function .onInit
        ; Code to run at installer startup
        Call MyCustomFunction
    FunctionEnd
!macroend

Real-World Example: CUDA Detection and Installation

Here’s a complete example that shows how to:

  • Detect NVIDIA GPUs
  • Check CUDA installation
  • Download and install CUDA if needed

Step 1: Create Variables

!macro customInit
    Var cudaVersion
    Var driverVersion
    Var cudaInstaller
    Var cudaInstallerUrl

Step 2: Create Detection Functions

Function DetectNvidiaGPU
    nsExec::ExecToStack 'wmic path win32_videocontroller get name'
    Pop $0
    Pop $1
    ${If} $1 contains "NVIDIA"
        StrCpy $0 "1"
    ${Else}
        StrCpy $0 "0"
    ${EndIf}
    Push $0
FunctionEnd

Step 3: Check Driver Version

Function GetNvidiaDriverVersion
    ReadRegStr $0 HKLM "SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{B2FE1952-0186-46C3-BAEC-A80AA35AC5B8}_Display.Driver" "DisplayVersion"
    Push $0
FunctionEnd

Step 4: Download and Install

Function InstallCuda
    DetailPrint "Downloading CUDA installer..."
    inetc::get "$cudaInstallerUrl" "$TEMP\cuda_installer.exe" /END
    ExecWait '"$TEMP\cuda_installer.exe" /s /noreboot'
    Delete "$TEMP\cuda_installer.exe"
FunctionEnd

Best Practices

  1. Always provide feedback to users about what’s happening
    • Use DetailPrint for installer progress
    • Use MessageBox for important decisions/information
  2. Handle errors gracefully
    • Check return values from commands
    • Provide fallback options
    • Don’t abort installation unless absolutely necessary
  3. Clean up after yourself
    • Remove temporary files
    • Close handles and connections
    • Don’t leave partial installations
  4. Respect user choice
    • Ask before downloading large files
    • Provide skip options for optional components
    • Remember user preferences

Common NSIS Commands

MessageBox MB_YESNO|MB_ICONQUESTION "Question?" IDNO label
    ; Shows a message box with Yes/No buttons

DetailPrint "Message"
    ; Shows progress in the installer

ExecWait "command" $0
    ; Runs a command and waits for completion

ReadRegStr $0 HKLM "Registry\Path" "ValueName"
    ; Reads from Windows Registry

${If} condition
${ElseIf} condition
${EndIf}
    ; Conditional statements

Debugging Tips

  1. Use DetailPrint to log progress
  2. Test installer with logging enabled: 
    hello-world-setup.exe /LOG=installer.log
  3. Check Windows Event Viewer for errors
  4. Test on clean virtual machines
  5. Verify elevated privileges when needed

Resources

Need Help?

Reach out to me on X @alexheloai

About the Author: Alex Ash is an AI engineer focusing on automation and cross-platform development. Contact at alex@helosolutions.ai or follow @alexheloai for more tutorials.