Question: how to run pxe boot?
Answer: Ensure that the PXE network environment is properly set up.
Reset or power on the server. ... 
Verify that PXE boot is enabled. ... 
On the BIOS screen, press the F8 key to specify a temporary boot device or press the F12 key to network boot (PXE). ... 
On the Please Select Boot Device menu, select the PXE boot port, and press Enter.