I recently had a problem where a User was being prompted for their credentials every time they would select the option to use ‘Open with Explorer” from the SharePoint Ribbon.
It took a while to narrow down the issue but it was discovered the the issue is that IE needs to open the Document Library using the WinHTTP service to access the WebDAV resource. To do this it needs to pass the currently logged in users credentials from IE to the HTTP service. This happens outside of IE security zones. Creating a registry value called AuthForwardServerList containing a multi-string value listing all of the WebDAV servers that we want to automatically forward credentials to will correct this behavior.
Following the steps here for adding the registry entry: http://support.microsoft.com/kb/943280
- Click Start, type regedit in the Start Search box, and then press ENTER.
- Locate and then click the following registry subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WebClient\Parameters
- On the Edit menu, point to New, and then click Multi-String Value.
- Type AuthForwardServerList, and then press ENTER.
- On the Edit menu, click Modify.
- In the Value data box, type the URL of the server that hosts the Web share, and then click OK.
Note You can also type a list of URLs in the Value data box. For more information, see the “Sample URL list” section in this article. - Exit Registry Editor.
Note: restart the WebClient service on the local machine for changes to be applied.
Just wanted to share this on our community jus in case someone needs it.