If you are installing Agent for Microsoft IIS 6.0 to protect Microsoft Office SharePoint, another task is required. To protect Microsoft Office SharePoint with this agent you must ensure that the authentication method for the Microsoft IIS 6.0 Server is set to Basic authentication as described in the task that follows.
Log in to the Microsoft IIS 6.0 Server as an administrator
In the Microsoft Windows Start menu, choose run.
Type the following: inetmgr
Expand the local computer.
Expand the Web Sites folder.
Right click Default Web Site.
An options list appears.
In the options list, click Properties.
The Default Web Site Properties dialog box appears.
Select the Directory Security tab.
Click Edit in the Authentication and access control section.
Select Basic authentication in the Authenticated access section.
Click OK again to close the Web site properties.
Now you can verify the installation of the agent as described in Microsoft Office SharePoint and Outlook Web Access: Verifying a Successful Agent Installation.