• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.

Deleted Uefi boot option (Windows Boot Manager) by mistake


Bavo

New Member
Posts
3
#1
Hallo,

After creating a UEFI bootable USB thumb drive with Rufus (using Windows 8.1 Enterprise ISO x64), for a Dell Optiplex 3010 (configured as UEFI only, no CSM, latest firmware version, Windows 8 installed), I didn't see a USB boot option, so I tried to add one manually. Unfortunately I erased the existing boot option (boot manager) by mistake. Although there were two boot options for PXE booting, the machine will not start anymore, even when there is an active WDS server on the network.

I also see Led's 2 and 3 lighting up, meaning according to the manual 'hardware ok but bios possibly damaged/corrupt'.

I understand I cannot start the machine from a bios boot disk because of GPT partitioning, and the UEFI USB boot disk I made might be corrupt (as it didn't show up as a boot option), however I don't understand why it won't boot from the PXE network card, as these boot options are still there.

Any suggestions on how to solve this?

Thanks for any useful tips,
Bavo
 

My Computer

System One

  • OS
    Windows 8.1

Saltgrass

New Member
Pro User
Posts
1,121
#2
The Windows Boot Manager is held in the Bios and restores itself if you boot to a UEFI capable device. Could you please explain exactly what you did to "Add" the USB boot option?

I haven't used Rufus since it is so easy to just format the drive yourself, but it did format in Fat32?

I have the PXE boot options disabled in my bios since I do not have a network boot option.
 

My Computer

System One

  • OS
    Windows 8.1 x64
    Computer type
    PC/Desktop
    System Manufacturer/Model Number
    Home Grown
    CPU
    i7 3770K
    Motherboard
    ASUS P8Z77 -v Pro, Z87-Expert
    Memory
    16 G
    Graphics Card(s)
    EVGA GTX 680 Classified (2)
    Hard Drives
    Kingston SSD 240 GB

Bavo

New Member
Posts
3
#3
I'm not an expert in uefi matters: when originally starting the (uefi) bios in the Dell, I only saw the Windows Boot Manager and PXE ipv4 & ipv6 entries as boot options, while the uefi usb stick was inserted. There is an 'add boot option' command button where you can browse for efi boot loaders to add them as boot options (these are *.efi files), so that is what i tried.
While trying out boot options and deleting them if they didn't work, that's where i accidently deleted the wrong boot option (Windows Boot Manager).

Remark1: the same usb thumb drive does show up in another (non dell) uefi machine as a boot option, so that is what i expected for the Dell machine. (and it proves there is nothing wrong with the boot drive produced by Rufus)

Remark2: I understand the uefi boot manager resides in firmware so i fully expected it to show an interface so I'd still at least see the PXE boot options, I know these work because that is how I usually install OS's. The problem is: nothing shows up after booting, just a blank screen and the two blinking LED's - I'm baffled...

Thanks for your reply,
Bavo

Rufus: I use it because it's quick and easy
 

My Computer

System One

  • OS
    Windows 8.1

Saltgrass

New Member
Pro User
Posts
1,121
#4
I have seen a bios that did show an add a boot option, but it was not for a normal Windows Boot Manager or UEFI type boot. Bioses are set up differently, so yours may work the way you believe. Have you tried updating or re-writing the bios?

You may want to check the BCD Store to see if the Windows Boot Manager is still listed as an option. You could use the command below in an Administrative Command Prompt and the attach it if you would like us to look at it.

bcdedit /enum all > %userprofile%\Desktop\bcdlist.txt

I suppose if you can't boot the system, you would need to boot to a recovery drive and send the output to a flash drive. I was going to suggest booting into the recovery drive, but I suppose that won't work if you can't get the system to boot a UEFI flash drive or an Install DVD.

If you boot with a UEFI capable flash drive and your bios is set up to see the UEFI option, it should show up as a boot option. If it is not, something is not set correctly. Possibly, in your case the red flashing lights might indicate something wrong on the motherboard. Mine has several flashing Leds and each one is a for different thing...no boot device/drive is one of them, along with memory and cpu.

The OptiPlex Dell Units listed on their site all show Windows 7 as the primary OS. Did you upgrade to Windows 8 and you are running the Enterprise version? Does that machine have any special configuration for business use that might be involved?
 

My Computer

System One

  • OS
    Windows 8.1 x64
    Computer type
    PC/Desktop
    System Manufacturer/Model Number
    Home Grown
    CPU
    i7 3770K
    Motherboard
    ASUS P8Z77 -v Pro, Z87-Expert
    Memory
    16 G
    Graphics Card(s)
    EVGA GTX 680 Classified (2)
    Hard Drives
    Kingston SSD 240 GB

Bavo

New Member
Posts
3
#5
Just spoke to a Dell technician: he suggested to remove the (CMOS) battery (litterally: turn it up side down for a second or two to create a small shortage, which should completely reset the internal firmware values, and check if you can reboot).
He also suggested that boot options not appearing could have something to do with the secure boot feature, so I should disable that when i have access again.

Finally he said that uefi bios implementation on the dell desktops is 'behind the times': they themselves usually revert to BIOS/MBR because of frequent problems. And all this straight from a Dell tech: at least he's forthcoming...

Next friday i have access to this machine, I'll let you know.

Best,
Bavo
 

My Computer

System One

  • OS
    Windows 8.1