How to Remove the PXE Boot
The Pre-boot Execution Environment was developed as a means to boot remote computer systems from a centrally managed server instead of through a computer's internal hard drive. This is particularly useful for embedded systems, such as those found in restaurants and point of sale systems. However, booting from the network via PXE may not be a desirable situation because it requires the use of a PXE server on the network. You can remove the option to boot from PXE by disabling the LAN BOOT ROM option of your network card in the computer's basic input/output system (BIOS) settings.
Power on or restart the computer, and then press the hotkey to enter the BIOS setup. Common keys are "F2" and "Del."
Navigate to the "Integrated Peripherals" section with the arrow keys on the keyboard.
Toggle the "LAN BOOT ROM" option to "Disabled." Your motherboard may refer to this as "PXE" instead.
Press the "F10" key to save the settings and exit the BIOS. The computer no longer attempts to boot from the network.