diff --git a/install.ps1 b/install.ps1
index 620f205..e2ed669 100644
--- a/install.ps1
+++ b/install.ps1
@@ -96,16 +96,13 @@ function Install-Octopus {
         try {
             $null = Invoke-WebRequest -Uri $releaseUrl -Method Head -UseBasicParsing -ErrorAction Stop
         } catch {
-            Write-Color "Error: Release v$specificVersion not found." "Red"
-            Write-Color "Available releases: $baseUrl/$REPO/releases" "DarkGray"
-            exit 1
+            throw "Release v$specificVersion not found. Available releases: $baseUrl/$REPO/releases"
         }
     } else {
         Write-Color "Fetching latest version..." "DarkGray"
         $specificVersion = Get-LatestVersion
         if (-not $specificVersion) {
-            Write-Color "Error: Failed to fetch latest version." "Red"
-            exit 1
+            throw "Failed to fetch latest version."
         }
     }
 
@@ -116,7 +113,7 @@ function Install-Octopus {
             $installedVersion = & $existing --version 2>$null
             if ($installedVersion -eq $specificVersion) {
                 Write-Color "Version $specificVersion already installed." "DarkGray"
-                exit 0
+                return
             } else {
                 Write-Color "Installed version: $installedVersion" "DarkGray"
             }
@@ -144,10 +141,8 @@ function Install-Octopus {
         $ProgressPreference = "SilentlyContinue"
         Invoke-WebRequest -Uri $downloadUrl -OutFile $zipPath -UseBasicParsing
     } catch {
-        Write-Color "Error: Failed to download $downloadUrl" "Red"
-        Write-Color $_.Exception.Message "Red"
         Remove-Item -Recurse -Force $tmpDir -ErrorAction SilentlyContinue
-        exit 1
+        throw "Failed to download $downloadUrl : $($_.Exception.Message)"
     }
 
     # Extract
@@ -157,9 +152,8 @@ function Install-Octopus {
     New-Item -ItemType Directory -Path $INSTALL_DIR -Force | Out-Null
     $exeSrc = Join-Path $tmpDir "$APP.exe"
     if (-not (Test-Path $exeSrc)) {
-        Write-Color "Error: $APP.exe not found in archive." "Red"
         Remove-Item -Recurse -Force $tmpDir -ErrorAction SilentlyContinue
-        exit 1
+        throw "$APP.exe not found in archive."
     }
     Copy-Item -Path $exeSrc -Destination (Join-Path $INSTALL_DIR "$APP.exe") -Force
     Remove-Item -Recurse -Force $tmpDir -ErrorAction SilentlyContinue
diff --git a/tests/test.ps1 b/tests/test.ps1
new file mode 100644
index 0000000..e8865ef
--- /dev/null
+++ b/tests/test.ps1
@@ -0,0 +1,75 @@
+#Requires -Version 5.1
+<#
+.SYNOPSIS
+    Regression tests for install.ps1.
+
+.BUG
+    `irm <url> | iex` closed the terminal window. Cause: the script used
+    `exit`, which under Invoke-Expression terminates the entire PowerShell
+    host process (there is no script scope to exit). Fix: use `return`
+    (success) / `throw` (errors) so the host survives.
+
+.NOTES
+    Host-process termination cannot be observed from inside the dying process,
+    so these tests combine a source-verification guard with a behavioral test
+    run in a child process (`exit` cannot be caught by try/catch and kills the
+    child; `throw` is catchable).
+#>
+[CmdletBinding()]
+param()
+
+Set-StrictMode -Version Latest
+$ErrorActionPreference = "Stop"
+
+$repoRoot      = Split-Path -Parent $PSScriptRoot
+$installScript = Join-Path $repoRoot "install.ps1"
+$failures      = [System.Collections.Generic.List[string]]::new()
+
+function Assert-True([bool]$Cond, [string]$Message) {
+    if (-not $Cond) { $failures.Add($Message) | Out-Null }
+}
+
+# --- Test 1 (source verification): no host-terminating `exit` ---
+$content   = Get-Content -Path $installScript -Raw
+$exitCount = ([regex]::Matches($content, '(?m)^\s*exit\b')).Count
+Assert-True ($exitCount -eq 0) "install.ps1 must not use bare 'exit' (found $exitCount); 'irm | iex' would kill the host. Use return/throw."
+
+# --- Test 2: parses cleanly ---
+$parseOk = $true
+try { [void][scriptblock]::Create($content) } catch { $parseOk = $false }
+Assert-True $parseOk "install.ps1 must parse without syntax errors."
+
+# --- Test 3 (behavioral): iex must NOT kill the host ---
+# Force the version lookup to fail fast against an unreachable address so the
+# script reaches its early-exit/throw path offline. `exit` terminates the child
+# (RESULT never emitted); `throw` is caught and RESULT is emitted.
+$inner = @'
+$ErrorActionPreference = "Stop"
+$env:OCTOPUS_DOWNLOAD_BASE = "http://127.0.0.1:1"
+$r = "nothing"
+try {
+    Invoke-Expression (Get-Content -Raw "__INSTALL__")
+    $r = "completed"
+} catch {
+    $r = "caught-throw"
+}
+Write-Output ("RESULT=$r")
+'@.Replace("__INSTALL__", $installScript)
+
+$tmp = Join-Path $env:TEMP ("octopus_iex_test_" + $PID + ".ps1")
+Set-Content -Path $tmp -Value $inner -Encoding UTF8
+try {
+    $childOut = (& powershell -NoProfile -File $tmp 2>&1 | Out-String)
+} finally {
+    Remove-Item $tmp -ErrorAction SilentlyContinue
+}
+Assert-True ($childOut -match 'RESULT=') "iex must not terminate the host (try/catch must observe a RESULT). Child output:`n$childOut"
+
+# --- Report ---
+if ($failures.Count -gt 0) {
+    Write-Host ("FAIL: " + $failures.Count + " test(s)") -ForegroundColor Red
+    foreach ($f in $failures) { Write-Host ("  - " + $f) -ForegroundColor Red }
+    exit 1
+}
+Write-Host "PASS: all regression tests passed." -ForegroundColor Green
+exit 0