You cannot deploy a single LMS-SOL driver across AMT generations. In the case of the HP 7700, 7800, and 7900 PCs, each model has a different AMT firmware generation. Each LMS-SOL driver must be matched to the AMT firmware version on that PC.
The vendor should provide an application to install for each system that you are deploying. This application was developed by Intel. On 2.6 and 3.x systems, it's called the AMT Status Monitor, and on AMT 4.0/5.0 it's called the Intel Manageability & Security Application.
The application installation should take care of installing the proper virtual serial port driver, the Local Manageability Service (LMS), the User Notification Service (UNS), and the Intel System Status Service.
FYI, the Intel Manageability & Security Application requires the Microsoft .NET Framework to run. I would recommend deploying the Microsoft .NET 3.5 SP1 Framework Redistributable package as a prerequisite to the Intel application package.