Event ID 5167 — IIS Worker Process Availability

Applies To: Windows Server 2008

Internet Information Services (IIS) worker processes serve an application pool and can be in a starting, running, stopping, or unknown state. In IIS 7.0, worker processes are managed by WAS (the Windows Process Activation Service). If a worker process fails to respond, it may be recycled by WAS.

Event Details

Product: Internet Information Services
ID: 5167
Source: Microsoft-Windows-WAS
Version: 7.0
Message: Windows Process Activation Service encountered an error trying to track worker process '%1' that belongs to app pool '%2'. This will result in this worker process not showing up in global queries enumerating all worker processes. It will also disable clients from being able to directly create a WORKER_PROCESS object to monitor this worker process. A client can see find this worker process by querying all worker processes in the app pool that this process belongs to. The data field contains the error number.


Check worker process initialization failure

If a worker process fails to initialize, check the event log message for a specific error number included in the message. This error number will be different from the Event ID. To do this, see the following steps.

To perform these procedures, you must have membership in Administrators, or you must have been delegated the appropriate authority.

Check for a specific error number

To check for a specific error number:

  1. In the Event Viewer, select the event that you received.
  2. Click the Details tab, then Friendly View.
  3. If a specific error number is available, the words Binary data: should appear.
  4. Below In Words, note the number after the colon.

Find out more about a specific error number

To learn more about a specific error number:

  1. Download the Err.exe utility from the Microsoft Exchange Server Error Code Look-up page.
  2. Open an elevated Command Prompt window. Click Start, point to All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.
  3. At the command prompt, navigate to the directory where you downloaded Err.exe. For example, if you downloaded Err.exe to C:\Err, type cd C:\Err.
  4. Type err errornumber to obtain more information about the error. For example, if the specific error number is 80070005, type err 80070005.
  5. In the example in Step 4, the error resolves to ERROR_ACCESS_DENIED, so your next step would be to check permissions related to the worker process.


You can use a browser client and IIS Manager to verify that an application pool worker process has started.

Note:  An IIS worker process does not exist until a request is made to the application pool for the Web application. For this reason, you may have to test browse the Web application before you can verify that a worker process is functional.

Test browse the application

To test browse the application:

  1. Open up your default browser or required client.
  2. Browse to the Web site or application whose worker process you want to test. The client should display the expected output page.

Verify that an application pool worker process is running

To perform this procedure, you must have membership in Administrators, or you must have been delegated the appropriate authority.

To verify that an application pool worker process is running:

  1. Click Start, click Control Panel, and then click Administrative Tools.
  2. Right-click Internet Information Services (IIS) Manager and select Run as administrator.
  3. In the Connections pane, select the computer name.
  4. In Features View, under the Feature Name column heading, double-click the Worker Processes management feature. A list of currently active application pools and worker processes will appear.
  5. The State column for the worker process will indicate Running if the worker process is running.
  6. You can also view currently executing requests by right-clicking the application pool name or worker process id and selecting View Current Requests.

IIS Worker Process Availability

Internet Information Services (IIS) 7.0