You may receive an "Access is denied" error message when you try to debug a Web application in Visual Studio .NET, and you have administrative permissions


You may receive the following error message when you try to debug a Web application:
Access is Denied
The problem occurs when the following conditions are true:
  • You are logged on to your computer with administrative permissions.
  • You are debugging a Web application in Microsoft Visual Studio .NET.
  • The operating system that you are using is Microsoft Windows XP Service Pack 2.
  • The Microsoft ASP.NET worker process account is not a member of the Administrators group.


The problem occurs because the ASP.NET worker process does not have the Impersonate a client after authentication user right. If the worker process account does not have this right, the debugger cannot attach to the process. The worker process account is configured by using the processModel element in the Machine.config file.


To give the worker process account the Impersonate a client after authentication user right, follow these steps:
  1. Click Start, point to
    Settings, and then click Control Panel.
  2. Double-click Administrative Tools.
  3. Double-click Local Security Policy.
  4. Expand Security Setting, expand
    Local Policies, and then click User Rights Assignment.
  5. In the Policy pane, right-click
    Impersonate a client after authentication, and then click
  6. Click Add User or Group.
  7. Add the worker process account that is configured in the processModel element in the Machine.config file.
  8. Click OK two times.
  9. Click Start, click Run, type iisreset, and then click
  10. At a command prompt, type the following command to refresh policies on the computer:
    gpupdate /force

Steps to reproduce the problem

  1. Open the Machine.config file. Locate the processModel element.
  2. Replace the username attribute and the password attribute as a non-administrative user.
  3. Restart Internet Information Services (IIS).
  4. Log off your computer. Log on your computer so that you have administrative permissions.
  5. Start Visual Studio .NET.
  6. Create a new Web application.

    When you try to debug the Web application, you may receive the following error message:
    Error while trying to run project: Unable to start debugging on the web server. Access is denied.
For more information about developing software in Visual Studio .NET that has non-administrative permissions, visit the following Microsoft Developer Network (MSDN) Web site:

ID do Artigo: 894433 - Última Revisão: 24 de mar de 2009 - Revisão: 1