diff --git a/scripts/install.ps1 b/scripts/install.ps1
new file mode 100644
index 0000000..c2cf743
--- /dev/null
+++ b/scripts/install.ps1
@@ -0,0 +1,121 @@
+#Requires -Version 5.1
+<#
+.SYNOPSIS
+    Install ctask to %LOCALAPPDATA%\ctask\bin on Windows.
+.DESCRIPTION
+    Builds ctask from the local repo, copies the binary and status-line helpers
+    to the install directory, and ensures the directory is on the user PATH.
+    Does not modify workspace data. Does not modify Claude Code settings.
+#>
+[CmdletBinding()]
+param()
+
+Set-StrictMode -Version Latest
+$ErrorActionPreference = 'Stop'
+
+$InstallDir = Join-Path $env:LOCALAPPDATA 'ctask\bin'
+
+# Find repo root (script lives in scripts/)
+$ScriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path
+$RepoRoot = Split-Path -Parent $ScriptDir
+
+if (-not (Test-Path (Join-Path $RepoRoot 'go.mod'))) {
+    Write-Error "Cannot find go.mod at $RepoRoot. Run this script from the ctask repo."
+    exit 1
+}
+
+Write-Host "ctask install" -ForegroundColor Cyan
+Write-Host "  Source:  $RepoRoot"
+Write-Host "  Target:  $InstallDir"
+Write-Host ""
+
+# Step 1: Find Go
+$GoExe = Get-Command go -ErrorAction SilentlyContinue | Select-Object -ExpandProperty Source
+if (-not $GoExe) {
+    # Check standard install location
+    $defaultGo = Join-Path $env:ProgramFiles 'Go\bin\go.exe'
+    if (Test-Path $defaultGo) {
+        $GoExe = $defaultGo
+    } else {
+        Write-Error "Go not found. Install Go (winget install GoLang.Go) and ensure it is on PATH."
+        exit 1
+    }
+}
+
+# Step 2: Build
+Write-Host "Building ctask..." -NoNewline
+Push-Location $RepoRoot
+try {
+    & $GoExe build -o ctask.exe . 2>&1 | Out-Null
+    if ($LASTEXITCODE -ne 0) {
+        Write-Host " FAILED" -ForegroundColor Red
+        Write-Error "Build failed. Check go build output."
+        exit 1
+    }
+    Write-Host " OK" -ForegroundColor Green
+} finally {
+    Pop-Location
+}
+
+# Step 2: Create install directory
+if (-not (Test-Path $InstallDir)) {
+    New-Item -ItemType Directory -Path $InstallDir -Force | Out-Null
+    Write-Host "  Created $InstallDir"
+}
+
+# Step 3: Copy files
+$filesToInstall = @(
+    @{ Src = Join-Path $RepoRoot 'ctask.exe';                    Dst = Join-Path $InstallDir 'ctask.exe' }
+    @{ Src = Join-Path $RepoRoot 'scripts\ctask-statusline.sh';  Dst = Join-Path $InstallDir 'ctask-statusline.sh' }
+    @{ Src = Join-Path $RepoRoot 'scripts\ctask-statusline.ps1'; Dst = Join-Path $InstallDir 'ctask-statusline.ps1' }
+)
+
+foreach ($f in $filesToInstall) {
+    if (Test-Path $f.Src) {
+        Copy-Item -Path $f.Src -Destination $f.Dst -Force
+        Write-Host "  Installed $(Split-Path -Leaf $f.Dst)"
+    } else {
+        Write-Warning "Source not found: $($f.Src)"
+    }
+}
+
+# Step 4: Ensure install directory is on user PATH
+$userPath = [Environment]::GetEnvironmentVariable('Path', 'User')
+if (-not $userPath) { $userPath = '' }
+$pathEntries = $userPath -split ';' | Where-Object { $_ -ne '' }
+
+if ($pathEntries -contains $InstallDir) {
+    Write-Host ""
+    Write-Host "  PATH: already contains $InstallDir" -ForegroundColor DarkGray
+} else {
+    $newPath = (($pathEntries + $InstallDir) | Where-Object { $_ -ne '' }) -join ';'
+    [Environment]::SetEnvironmentVariable('Path', $newPath, 'User')
+
+    # Write ownership marker so uninstall knows we added this entry
+    $marker = Join-Path $InstallDir '.ctask-path-added'
+    Set-Content -Path $marker -Value "PATH entry added by ctask install on $(Get-Date -Format 'yyyy-MM-dd HH:mm:ss')"
+
+    Write-Host ""
+    Write-Host "  PATH: added $InstallDir" -ForegroundColor Green
+    Write-Host "  NOTE: Open a new terminal for PATH changes to take effect." -ForegroundColor Yellow
+}
+
+# Step 5: Verify
+$installedBinary = Join-Path $InstallDir 'ctask.exe'
+if (Test-Path $installedBinary) {
+    $ver = & $installedBinary --version 2>&1
+    Write-Host ""
+    Write-Host "Installed: $ver" -ForegroundColor Green
+} else {
+    Write-Warning "Binary not found at $installedBinary"
+    exit 1
+}
+
+# Step 6: Clean up build artifact from repo root
+$repoExe = Join-Path $RepoRoot 'ctask.exe'
+if (Test-Path $repoExe) {
+    Remove-Item $repoExe -Force
+}
+
+Write-Host ""
+Write-Host "Run 'ctask doctor' in a new terminal to verify setup." -ForegroundColor Cyan