You can modify the Windows registry to allow Basic authentication to WebDAV over an HTTP connection. This registry change allows users to use Microsoft Office 2007 on the Windows 7 operating system, but does not allow them to use Microsoft Office 2010. Microsoft Office 2010 is not supported with Basic Authentication over an HTTP connection.
To modify the Windows registry:
On each Windows 7 workstation, click Start > Run, then specify regedit in the Open field.
Click OK.
In the Registry Editor window, navigate to the following registry entry:
\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlset\services\WebClient\Parameters\BasicAuthLevel
Change the value of this registry entry to 2.
Navigate to the Services interface, then restart the WebClient service.