The Windows Share Web Client available in Modules and plugins references ../../auth/ldap/lib.php which is no longer distributed with Moodle as of version 1.8.
This makes the block non-functional in a default installation of Moodle.
I looked at the code and discovered that all the functions referenced in lib.php are available in auth.php, so I modified the code to use auth.php instead of lib.php.
Attached is the block, tested and working on both 1.8 and 1.9. I have also modified the block so it only appears if the user is logged into the system.