Solved unknown devices in Windows 7 Enterprise (x64) OS on Dell Optiplex GX960 pc (Rev: 1.0)

After installing Windows 7 Enterprise (x64) Operating System (OS) on the Dell Optiplex GX960 computer with 8 GB DDR2 800 Mhz SDRAM memory, there are 2 unknown devices in the Control Panel -> System -> Hardware -> Device Manager as shown below:

1. PCI Communication Controller
-> Installing the device drivers using Intel AMT HECI (from Chipset category) version 5.2.10.1023 PV, A02 from DELL.

2. PCI serial port
-> Installing the device drivers using Intel AMT SOL/LMS (from Chipset category) version 5.2.10.1023 PV, A02 from DELL.