Event ID 33 — WUA Update Download

Applies To: Windows Server 2008 R2

Windows Update Agent downloads updates from Windows Update, Microsoft Update, or Windows Server Update Services. Windows Update Agent can be configured to automatically detect and download updates or can be set to manually download updates by the user.

Event Details

Product: Windows Operating System
ID: 33
Source: Microsoft-Windows-WindowsUpdateClient
Version: 6.1
Message: Windows Update was unable to connect to proxy server %1 because valid credentials (user name and password) were required, but were either not available or were incorrect. Please check your proxy credentials, and then try searching again for updates.


Correct proxy authorization problems

The Microsoft Windows Update client program requires Windows HTTP Services (WinHTTP) to scan for available updates. In addition, the Windows Update client uses Background Intelligent Transfer Service (BITS) to download these updates. WinHTTP and BITS run independently of Microsoft Internet Explorer. Both these services must be able to detect the proxy server or proxy servers that are available in your particular environment.

To check that your client computer can connect to the local proxy server:

  1. Ensure that autodetect is selected in Internet Explorer: Open Internet Explorer, click Tools, click Internet Options, click Connections, choose the network settings, and click LAN settings. Ensure that the Automatically detect settings check box is selected.
  2. If autodetect is selected in Internet Explorer proxy settings, check WinHTTP proxy settings by following steps 3 and 4.
  3. If running Windows Vista, open the Command Prompt window and type netsh winhttp show proxy.
  4. If the proxy server is correct, retry detection by opening the Command Prompt window and typing wuapp.
  5. When you have ensured that you are connected to the correct proxy server, check that the correct credentials are being used.


To confirm Windows Update Agent is downloading updates successfully when Automatic Updates is on:

  1. Open an elevated Command Prompt window. Click Start, point to All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.
  2. Type wuauclt /detectnow, and then press ENTER.
  3. At the command prompt, type eventvwr.msc and press ENTER to open Event Viewer.
  4. To check for events in Event Viewer:
    1. In the left panel of Event Viewer, click Application and Service Logs.
    2. Expand Microsoft, and then expand Windows.
    3. Click WindowsUpdateClient, and then click Operational.
    4. Check to see if Event ID 41 is present in the event list to confirm that Windows Update Agent has successfully downloaded the updates.

WUA Update Download

Windows Update