When a newly installed network card is not being recognized by the operating system, the most likely cause is that the necessary driver is not installed or loaded. Device drivers act as intermediaries between the hardware and the operating system. Without the correct driver, the OS cannot communicate with or properly use the network card.
Other Options:
* A. The network cable is unplugged: This would prevent network connectivity, but the OS would still recognize the network card itself.
* C. The IP settings are incorrect: Incorrect IP settings can cause network issues but do not prevent the OS from recognizing the NIC.
* D. PXE boot is enabled: PXE (Preboot Execution Environment) allows a system to boot from a network rather than a local disk. While PXE may affect booting, it does not directly cause a NIC to be unrecognized by the OS.
Thus, the most likely cause is that the driver for the network card is not installed or properly loaded.
References:
* CompTIA Server+ Certification Exam Objectives (SK0-005): Server Hardware - Explain server components and their functions