Client Manager is a software for the TrueMobile 1150 Wireless PC card.
In order to use the Dell Truemobile 1150 wireless cards with midd_secure, you will need to update the drivers and the wireless client manager.
You'll have to install the client manager first (run the executible and keep clicking OK), then upgrade the drivers. There is an HTML file that opens automatically once you install the drivers, this walks you through the driver update process. When you update the driver you will be prompted to create a wireless profile it's easiest to skip this step and just leave the Default profile as the only profile.