HP Compaq 8200 Elite stuck in Initializing Intel Boot Agent even though PXE boot disabled

[roming-eye]

I have an HP Compaq 8200 Elite minitower, and I bought 2 HP NC364T quad port server network cards.  The computer has a bootable hard disk and has CentOS 7 installed.  Before installing the network cards, the computer is able to boot with CentOS 7.

When I plug 2 HP quad port network cards into the PCIe 16 slots, and turn on the computer, the following message is displayed on the screen:

Initializing Intel(R) Boot Agent GE v1.3.72
PXE 2.1 Build 089 (WfM 2.0)

I turn off the computer and turn on again.

After powering on the computer, I immediately press the Escape key repeatedly trying to bring up the BIOS menu.  However, it never appears and the above "Initializing Intel Boot Agent ..." message is displayed.

I turn off the computer and turn on again.

After powering on the computer again, I immediately press the F10 key repeatedly trying to bring up the BIOS menu.  Again, it never appears and the "Initializing Intel Boot Agent ..." message is displayed.

When I remove one of the HP network cards, the "Initializing Intel Boot Agent ..." message is not displayed.  The computer is able to boot with CentOS 7.  The computer is able to boot as long as only 1 of the HP quad port network cards is plugged in.  I have one of the quad port network cards in one of the PCIe slot and booted to CentOS.  I then moved the quad port to the other PCIe slot and was again able to boot to CentOS.

I have disabled PXE using the following procedure:

I have 1 HP quad port network card plugged in.

I turn on the computer and press F10

From the BIOS Setup:

I go to Advanced >> Device Options >> NIC Option ROM Download >> Disabled

Press F10 to accept

From  the BIOS Setup:

I go to Security >> Network Boot >> Disabled

Press F10 to accept

From the BIOS Setup:

I go to Storage >> Boot Order >> Legacy Boot Sources

I press the down arrow key and place the arrow on a Network Controller and press F5 to disable

I repeat for each listed Network Controller under Legacy Boot Sources

Press F10 to accept

From the BIOS Setup:

I go to File >> Save Changes and Exit

Press enter

Press enter on Yes

The computer restarts, and I let it boot to CentOS

I shutdown the computer I plug in the second HP quad port network card, so 2 network cards are installed.

I turn on the computer again, and the "Initializing Intel Boot Agent ..." message is displayed again.

I shutdown the computer and remove the second network card.

I turn on the computer and press F10 repeatedly to go the BIOS Setup.

I go to Storage >> Boot Order

In the Boot Order dialog, Network Controller is not listed at all.

I am setting up this Compaq Elite 8200 minitower to be a Linux network router/gateway need to have 2 quad port network cards installed.  I also need to have the built-in network card on the motherboard enabled, so it can be used as a console port.

What can I do to disable or remove the "Initializing Intel Boot Agent ..." and boot to Linux with 2 quad port network cards installed.