How to fix a "PXE-E61" boot error on a Dell 9010

If you unplug a Dell 9010 when the lithium battery is dead or removed the BIOS will be messed up and the computer will behave as though your hard drive is dead with the PXE-E61 error.  But you can fix it by following the steps below.   (Note my Dell 9010's are running Windows 10 as either 32-bt or 64-bit; the procedure is the same for both).

1) Safe boot the computer:
   a- Ensure the computer is off.
   b- Press AND HOLD F12 and turn on the computer.
   c- When writing appears on the monitor, release F12
   d- Wait until a menu appears.

2) Obtain the BIOS Setup menu:
   a- Press the arrow down key until "BIOS Setup" is highlighted.
   b- Press Enter.

3) Change boot settings:
   a- Click on "Boot Sequence"
   b- Click on "UEFI" so it is selected.
   c- Click on "Advanced Boot Options"
   d- Click on the box by "Enable Legacy Option Roms" so unchecked.

4) Change Configurations:
   a- Click on "System Configuration"
   b- Press Enter and a submenu appears.
   c- Click on "Integrated NIC"
   d- Click on "Enabled" (NOT "Enabled w/PXE") so it is selected.
   e- Click on "SATA operation"
   f- Click on "AHCI" so it is selected

5) Save settings:
   a- Click on "Apply" at bottom right,
   b- Click on "Exit" and wait for reboot.

If you want to check (or replace) your lithium battery in a Dell 9010, you MUST remove the battery with the computer turned off but plugged in!  If you don't, you will mess up the BIOS and have to go through the steps above.  I have pasted these instructions to all of my Dell 9010's!