Unable to open webfolders on Windows Vista when Forms Based Authentication is used on ISA Server 2006

Unable to open webfolders on Windows Vista when Forms Based Authentication is used on ISA Server 2006


You are unable to connect to a document library in SharePoint using Windows Explorer or by using the Explorer view. This problem affects the following operating systems:

  • Windows Vista
  • Windows XP SP3 or Later

This issue occurs if you use Forms Based Authentication (example below) to access the SharePoint site from the internet and your SharePoint site is configured to use Integrated Authentication.

ISA Server 2006 Forms Based Authentication

When Active Directory is used for the authentication mechanism for Forms Based Authentication it uses Basic Authentication to authenticate you with Active Directory. For security reasons Windows Vista disables Basic Authentication in WebDAV. WebDAV is the mechanism that is used in SharePoint to present the Site as folder in Windows Explorer.


There are two ways to resolve this problem:

1. Use SSL publish your SharePoint site. You will need to purchase a certificate and install it on the ISA server and then use HTTPS to HTTP bridging to the SharePoint server.

2. Enable basic authentication on the client computer. This involves editing the registry on each computer that has the problem.

To enable Basic authentication on the client computer, follow these steps: 

1. Click Start  Start button , type regedit in the Start Search box, and then click regedit.exe in the Programs list.
2. Locate and then click the following registry key:
3. On the Edit menu, point to New, and then click DWORD Value.
4. Type BasicAuthLevel, and then press ENTER.
5. On the Edit menu, click Modify.

In the Value data box, type 2, and then click OK.

7. Exit Registry Editor, and then restart the computer.




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