diff --git a/install-codex-cli.ps1 b/install-codex-cli.ps1
index 9645ddc..92fe46c 100644
--- a/install-codex-cli.ps1
+++ b/install-codex-cli.ps1
@@ -48,24 +48,33 @@ function Main {
     Write-Info "===== Codex CLI install script (Windows PowerShell) ====="
     Write-Info "Installing OpenAI Codex CLI natively..."
 
+    $tmpDir = Join-Path $env:TEMP "codex_install_$(Get-Random)"
+    New-Item -ItemType Directory -Path $tmpDir -Force | Out-Null
+    $scriptPath = Join-Path $tmpDir "install.ps1"
+
     try {
-        Write-Info "Fetching and executing official installer from: https://chatgpt.com/codex/install.ps1"
-        
-        # 공식 설치 ps1 스크립트를 다운로드 및 메모리 상에서 직접 호출 가동
-        $installerScript = Invoke-RestMethod -Uri "https://chatgpt.com/codex/install.ps1" -UseBasicParsing
-        Invoke-Expression $installerScript
+        Write-Info "Downloading official installer from: https://releases.openai.com/codex/install.ps1"
+        $ProgressPreference = 'SilentlyContinue'
+        Invoke-WebRequest -Uri "https://releases.openai.com/codex/install.ps1" -OutFile $scriptPath -UseBasicParsing
+        $ProgressPreference = 'Continue'
+
+        if (-not (Test-Path $scriptPath)) {
+            Write-Err "Failed to download official Codex CLI installer."
+        }
+
+        Write-Info "Executing official Codex CLI installer..."
+        & $scriptPath
 
         Write-Success "Codex CLI has been successfully installed!"
         Write-Info "Please restart your terminal window or refresh your PATH environment variable."
         Write-Info "Run command: codex auth (to log in) and then 'codex' to start."
     } catch {
         Write-Err "Failed to install Codex CLI: $_"
+    } finally {
+        if (Test-Path $tmpDir) {
+            Remove-Item -Path $tmpDir -Recurse -Force -ErrorAction SilentlyContinue
+        }
     }
 }
 
-# 예기치 못한 전체 프로세스 에러 감지를 위한 Trap 설정
-trap {
-    Write-Err "An unexpected error occurred during installation: $_"
-}
-
 Main