Error: Debugging Failed Because Integrated Windows Authentication Is Not Enabled
Authentication of the user who requested debugging was prevented by an authentication error. This can occur when you try to step into a Web application or an XML Web service. One cause of this error is that integrated Windows authentication is not enabled. To enable it, follow the steps in "To enable integrated Windows authentication."
If you have enabled integrated Windows authentication and this error still appears, it is possible that this error is caused because Digest Authentication for Windows Domain Servers is enabled. In this situation you should contact with your network administrator.
To enable integrated Windows authentication
Log on to the Web server by using an administrator account.
Click Start and then click Control Panel.
In Control Panel, double-click Administrative Tools.
Double-click Internet Information Services.
Click the Web server node.
A Web Sites folder opens underneath the server name.
You can configure authentication for all Web sites or for individual Web sites. To configure authentication for all Web sites, right-click the Web Sites folder and then click Properties. To configure authentication for an individual Web site, open the Web Sites folder, right-click the individual Web site, and then click Properties.
The Properties dialog box is displayed.
Click the Directory Security tab.
In the Anonymous access and authentication control section, click Edit.
The Authentication Methods dialog box is displayed.
Under Authenticated access, select Integrated Windows authentication.
Click OK to close the Authentication Methods dialog box.
Click OK to close the Properties dialog box.
Close the Internet Information Services window.
To enable integrated Windows authentication in older versions of Windows and IIS.
See Running Web Applications with IIS 7.0 and Visual Studio