diff --git a/install.ps1 b/install.ps1
index 03876cb..469c98a 100644
--- a/install.ps1
+++ b/install.ps1
@@ -1,26 +1,26 @@
 # Windows PowerShell installation script for Komari Agent
 
 # Logging functions with colors
-function Log-Info   { Write-Host "[INFO]    $($_)"    -ForegroundColor Cyan }
-function Log-Success{ Write-Host "[SUCCESS] $($_)"    -ForegroundColor Green }
-function Log-Warning{ Write-Host "[WARNING] $($_)"    -ForegroundColor Yellow }
-function Log-Error  { Write-Host "[ERROR]   $($_)"    -ForegroundColor Red }
-function Log-Step   { Write-Host "[STEP]    $($_)"    -ForegroundColor Magenta }
-function Log-Config { Write-Host "[CONFIG]  $($_)"    -ForegroundColor White }
+function Log-Info { param([string]$Message) Write-Host "$Message"    -ForegroundColor Cyan }
+function Log-Success { param([string]$Message) Write-Host "$Message"    -ForegroundColor Green }
+function Log-Warning { param([string]$Message) Write-Host "[WARNING] $Message"    -ForegroundColor Yellow }
+function Log-Error { param([string]$Message) Write-Host "[ERROR] $Message"    -ForegroundColor Red }
+function Log-Step { param([string]$Message) Write-Host "$Message"    -ForegroundColor Magenta }
+function Log-Config { param([string]$Message) Write-Host "- $Message"    -ForegroundColor White }
 
 # Default parameters
-$InstallDir      = Join-Path $Env:ProgramFiles "Komari"
-$ServiceName     = "komari-agent"
-$GitHubProxy     = ""
-$KomariArgs      = @()
+$InstallDir = Join-Path $Env:ProgramFiles "Komari"
+$ServiceName = "komari-agent"
+$GitHubProxy = ""
+$KomariArgs = @()
 
 # Parse script arguments
 for ($i = 0; $i -lt $args.Count; $i++) {
     switch ($args[$i]) {
-        "--install-dir"          { $InstallDir = $args[$i+1]; $i++; continue }
-        "--install-service-name" { $ServiceName = $args[$i+1]; $i++; continue }
-        "--install-ghproxy"      { $GitHubProxy = $args[$i+1]; $i++; continue }
-        Default                    { $KomariArgs += $args[$i] }
+        "--install-dir" { $InstallDir = $args[$i + 1]; $i++; continue }
+        "--install-service-name" { $ServiceName = $args[$i + 1]; $i++; continue }
+        "--install-ghproxy" { $GitHubProxy = $args[$i + 1]; $i++; continue }
+        Default { $KomariArgs += $args[$i] }
     }
 }
 
@@ -41,6 +41,118 @@ switch ($env:PROCESSOR_ARCHITECTURE) {
     Default { Log-Error "Unsupported architecture: $env:PROCESSOR_ARCHITECTURE"; exit 1 }
 }
 
+# Ensure installation directory exists for nssm and agent
+Log-Step "Ensuring installation directory exists: $InstallDir"
+New-Item -ItemType Directory -Path $InstallDir -Force -ErrorAction SilentlyContinue | Out-Null # Ensure $InstallDir exists
+
+# Check for nssm and download if not present
+$nssmExeToUse = Join-Path $InstallDir "nssm.exe"
+
+# First, check if nssm is in PATH and is functional
+$nssmCmd = Get-Command nssm -ErrorAction SilentlyContinue
+if ($nssmCmd) {
+    Log-Info "nssm found in PATH at $($nssmCmd.Source)."
+    try {
+        $nssmVersionOutput = nssm version 2>&1
+        Log-Info "Detected nssm version: $nssmVersionOutput"
+    }
+    catch {
+        Log-Warning "nssm found in PATH failed to execute 'nssm version'. Will attempt to use/download local copy. Error: $_"
+        $nssmCmd = $null # Force re-evaluation for local copy or download
+    }
+}
+
+# If nssm not found in PATH or the one in PATH failed, check local $InstallDir
+if (-not $nssmCmd) {
+    if (Test-Path $nssmExeToUse) {
+        Log-Info "nssm found at $nssmExeToUse. Attempting to use it by adding $InstallDir to PATH."
+        $env:Path = "$($InstallDir);$($env:Path)"
+        $nssmCmd = Get-Command nssm -ErrorAction SilentlyContinue
+        if ($nssmCmd) {
+            try {
+                $nssmVersionOutput = nssm version 2>&1
+            }
+            catch {
+                Log-Warning "nssm from $InstallDir failed to execute 'nssm version'. Error: $_"
+                $nssmCmd = $null # Mark as unusable
+            }
+        }
+        else {
+            Log-Warning "Failed to make nssm from $nssmExeToUse available via PATH. Will attempt download."
+        }
+    }
+}
+
+# If still no usable nssm command, proceed to download
+if (-not $nssmCmd) {
+    Log-Info "nssm not found or not usable. Attempting to download to $InstallDir..."
+    $NssmVersion = "2.24"
+    $NssmZipUrl = "https://nssm.cc/release/nssm-$NssmVersion.zip"
+    $TempNssmZipPath = Join-Path $env:TEMP "nssm-$NssmVersion.zip"
+    $TempExtractDir = Join-Path $env:TEMP "nssm_extract_temp"
+
+    try {
+        Log-Info "Downloading nssm from $NssmZipUrl..."
+        Invoke-WebRequest -Uri $NssmZipUrl -OutFile $TempNssmZipPath -UseBasicParsing
+
+        if (Test-Path $TempExtractDir) { Remove-Item -Recurse -Force $TempExtractDir }
+        New-Item -ItemType Directory -Path $TempExtractDir -Force | Out-Null
+        Expand-Archive -Path $TempNssmZipPath -DestinationPath $TempExtractDir -Force
+        
+        $NssmSourceDirInsideZip = "nssm-$NssmVersion" # Used for Get-ChildItem search path
+        # The path part within the extracted nssm folder, e.g., "nssm-2.24\win32"
+        # 'win32' nssm is used for both 'amd64' and 'arm64' PowerShell architectures.
+        $NssmArchSubDir = Join-Path "nssm-$NssmVersion" "win32"
+        $NssmSourceExePath = Join-Path (Join-Path $TempExtractDir $NssmArchSubDir) "nssm.exe"
+
+        if (-not (Test-Path $NssmSourceExePath)) {
+            Log-Error "Could not find nssm.exe at expected path: $NssmSourceExePath after extraction."
+            # Fallback search for nssm.exe within the extracted directory
+            $foundNssmFallback = Get-ChildItem -Path $TempExtractDir -Recurse -Filter "nssm.exe" | 
+            Where-Object { $_.FullName -like "*$NssmArchSubDir\nssm.exe" } | 
+            Select-Object -First 1
+            if ($foundNssmFallback) {
+                Log-Warning "Found nssm.exe at $($foundNssmFallback.FullName) using fallback search. Using this."
+                $NssmSourceExePath = $foundNssmFallback.FullName
+            }
+            else {
+                Log-Error "nssm.exe ($NssmArchSubDir) still not found in $TempExtractDir. Please install nssm manually (from https://nssm.cc) and ensure it's in your PATH."
+                exit 1
+            }
+        }
+        
+        Copy-Item -Path $NssmSourceExePath -Destination $nssmExeToUse -Force
+
+        $env:Path = "$($InstallDir);$($env:Path)"
+        $nssmCmd = Get-Command nssm -ErrorAction SilentlyContinue # Re-check after adding to PATH
+        if ($nssmCmd) {
+            Log-Success "Downloaded nssm is now configured and available in PATH."
+        }
+        else {
+            Log-Error "Failed to configure downloaded nssm in PATH from $nssmExeToUse. Please ensure $InstallDir is in your system PATH or nssm is installed globally."
+            exit 1
+        }
+    }
+    catch {
+        Log-Error "Failed to download or configure nssm: $_"
+        Log-Error "Please install nssm manually from https://nssm.cc and ensure nssm.exe is in your PATH."
+        exit 1
+    }
+    finally {
+        if (Test-Path $TempNssmZipPath) { Remove-Item $TempNssmZipPath -Force -ErrorAction SilentlyContinue }
+        if (Test-Path $TempExtractDir) { Remove-Item $TempExtractDir -Recurse -Force -ErrorAction SilentlyContinue }
+    }
+}
+
+# Final check that nssm is operational
+try {
+    $nssmVersionOutput = nssm version 2>&1
+}
+catch {
+    Log-Error "nssm command failed to execute even after setup attempts. Please check the nssm installation and PATH. Error: $_"
+    exit 1
+}
+
 Log-Step "Installation configuration:"
 Log-Config "Service name: $ServiceName"
 Log-Config "Install directory: $InstallDir"
@@ -48,21 +160,39 @@ Log-Config "GitHub proxy: $ProxyDisplay"
 Log-Config "Agent arguments: $($KomariArgs -join ' ')"
 
 # Paths
-$BinaryName   = "komari-agent-windows-$arch.exe"
-$AgentPath    = Join-Path $InstallDir $BinaryName
+$BinaryName = "komari-agent-windows-$arch.exe"
+$AgentPath = Join-Path $InstallDir "komari-agent.exe"
 
 # Uninstall previous service and binary
 function Uninstall-Previous {
     Log-Step "Checking for existing service..."
-    $svc = Get-Service -Name $ServiceName -ErrorAction SilentlyContinue
-    if ($svc) {
+    # Check if service exists using nssm status, as Get-Service might not work for nssm services if not properly registered
+    $serviceStatus = nssm status $ServiceName 2>&1
+    if ($serviceStatus -notmatch "SERVICE_STOPPED" -and $serviceStatus -notmatch "does not exist") {
         Log-Info "Stopping service $ServiceName..."
-        Stop-Service $ServiceName -Force
-        Log-Info "Deleting service $ServiceName..."
-        sc.exe delete $ServiceName | Out-Null
+        nssm stop $ServiceName 2>&1 | Out-Null
     }
+    # Attempt to remove the service using nssm
+    # We check if it exists first by trying to get its status.
+    # nssm remove will succeed if the service exists, and fail otherwise.
+    # We add confirm to avoid interactive prompts.
+    $removeOutput = nssm remove $ServiceName confirm 2>&1
+    if ($LASTEXITCODE -eq 0) {
+    }
+    elseif ($removeOutput -match "Can't open service! (The specified service does not exist as an installed service.)" -or $removeOutput -match "No such service" -or $removeOutput -match "does not exist") {
+        Log-Info "Service $ServiceName does not exist or was already removed."
+    }
+    else {
+        # If nssm remove fails for other reasons, try sc.exe delete as a fallback for older installations
+        $svc = Get-Service -Name $ServiceName -ErrorAction SilentlyContinue
+        if ($svc) {
+            Stop-Service $ServiceName -Force -ErrorAction SilentlyContinue
+            sc.exe delete $ServiceName | Out-Null
+        }
+    }
+
     if (Test-Path $AgentPath) {
-        Log-Info "Removing old binary..."
+        Log-Warning "Removing old binary..."
         Remove-Item $AgentPath -Force
     }
 }
@@ -70,39 +200,46 @@ Uninstall-Previous
 
 # Fetch latest release version
 $ApiUrl = "https://api.github.com/repos/komari-monitor/komari-agent/releases/latest"
-Log-Step "Fetching latest version from GitHub API..."
 try {
-    $release        = Invoke-RestMethod -Uri $ApiUrl -UseBasicParsing
-    $latestVersion  = $release.tag_name
-} catch {
+    $release = Invoke-RestMethod -Uri $ApiUrl -UseBasicParsing
+    $latestVersion = $release.tag_name
+}
+catch {
     Log-Error "Failed to fetch latest version: $_"
     exit 1
 }
 Log-Success "Latest version: $latestVersion"
 
 # Construct download URL
-$BinaryName  = "komari-agent-windows-$arch.exe"
+$BinaryName = "komari-agent-windows-$arch.exe"
 $DownloadUrl = if ($GitHubProxy) { "$GitHubProxy/https://github.com/komari-monitor/komari-agent/releases/download/$latestVersion/$BinaryName" } else { "https://github.com/komari-monitor/komari-agent/releases/download/$latestVersion/$BinaryName" }
 
 # Download and install
-Log-Step "Preparing installation directory..."
 New-Item -ItemType Directory -Path $InstallDir -Force | Out-Null
-Log-Step "Downloading $BinaryName..."
 Log-Info "URL: $DownloadUrl"
 try {
     Invoke-WebRequest -Uri $DownloadUrl -OutFile $AgentPath -UseBasicParsing
-} catch {
+}
+catch {
     Log-Error "Download failed: $_"
     exit 1
 }
 Log-Success "Downloaded and saved to $AgentPath"
 
 # Register and start service
-Log-Step "Configuring Windows service..."
+Log-Step "Configuring Windows service with nssm..."
 $argString = $KomariArgs -join ' '
-New-Service -Name $ServiceName -BinaryPathName "`"$AgentPath`" $argString" -DisplayName "Komari Agent Service" -StartupType Automatic
-Start-Service $ServiceName
-Log-Success "Service $ServiceName installed and started."
+# Ensure InstallDir and AgentPath are quoted if they contain spaces
+$quotedAgentPath = "`"$AgentPath`""
+nssm install $ServiceName $quotedAgentPath $argString
+# Set display name and startup type using nssm
+nssm set $ServiceName DisplayName "Komari Agent Service"
+nssm set $ServiceName Start SERVICE_AUTO_START
+nssm set $ServiceName AppExit Default Restart
+nssm set $ServiceName AppRestartDelay 5000
+# Start the service using nssm
+nssm start $ServiceName
+Log-Success "Service $ServiceName installed and started using nssm."
 
 Log-Success "Komari Agent installation completed!"
 Log-Config "Service name: $ServiceName"