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Re: Windows 10 Boot Manager Missing

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Paul

unread,
Aug 4, 2018, 12:31:37 AM8/4/18
to
Boris wrote:
> I messed up.
>
> Machine is a Dell 3668 Laptop running Windows 10 version 1803.
>
> I wanted to run a live Linux distribution DVD (like I have on this Windows
> 7 machine), but of course I needed to set the Dell 3668 to boot from
> CD/DVD.
>
> I had the DVD in the Toshiba optical drive.
>
> This boot entry was not in the "Boot Sequence" of the UEFI BIOS. I
> followed these instructions to try to make this entry available as a boot
> selection.
>
> https://www.dell.com/support/article/us/en/19/sln142679/how-to-enable-
> boot-from-dvd-option-with-uefi-boot-mode-enabled-windows-8-81-10-?lang=en
>
> Before I made any changes, the boot sequence showed Windows Boot Manager,
> with one option, my hard drive.
>
> I disabled Secure Boot, made sure UEFI was enabled, and followed the rest
> of the directions.
>
> When I entered "CD/DVD/CD-RW Drive", but there was only the existing hard
> drive in the File System List field. There was nothing about a CD, yet
> System Information (in the UEFI BIOS) showed there was an optical hard
> drive.
>
> I pressed ok, and of course it said no path, or something like that.
> (Couldn't take screen shots while in UEFI, and figured I'd just be booted
> out to start in Windows 10 at some point. But, no.
>
> I powered up the machine and tapped F12 to get into the UEFI.
>
> I now had the following selection:
>
> CD/DVD/CD-RW Drive
> UEFI My Windows Hard drive
> UEFI Toshiba DVD
>
> No matter whatI selected from above, I was booted into Windows 10.
>
> I got back into the UEFI, but now I had no Windows Boot Manager, let alone
> My Windows Hard drive appearing. But, I could still boot into Windows 10
> by selecting any of the other two.
>
> How do I get my Windows Boot Manager back so I can try again? Is it as
> simple as repairing the boot manager?
>
> Thanks

https://www.dell.com/support/article/ca/en/cabsdt1/sln245206/how-to-restore-the-bios-system-setup-defaults-on-a-dell-product?lang=en

F2.

"Restore Settings" or "Load Defaults"

[There would normally be a "Save and Exit" option too.]

*******

You have to be a bit careful with early UEFI or EFI systems,
because they expose a bit too much of the NVRAM variable
storage.

On one computer (perhaps an Asus), it was possible to remove
an NVRAM entry from the OS, for which the BIOS was missing
an option to put it back.

In another case, a BIOS bug used up all the NVRAM storage,
leading to some sort of brickage.

Later UEFI BIOS aren't quite as bad.

The system really shouldn't be showing you NVRAM strings
in the interface. It should show "Toshiba 1234 DVD" or the
like and not giving bus nomenclature. How is the user supposed
to know this nomenclature ? This is unnecessarily confusing.
Maybe they could drop to assembler code for shits and giggles ???

*******

There are two steps that need to be taken.

1) Enter BIOS setup and make sure you do something
about secure boot.
2) If you feel you need it, enable Legacy BIOS Support
(also known as Compatibility Support Module or CSM).
Not all BIOS support both UEFI&CSM at the same time,
but at least mine does.

Now save and exit the BIOS. These steps are
needed to expose enough of the controls, so you
can run other OSes. I don't think Windows cares
at this point, but it's always possible you
might have to turn Secure Boot back on some day.
I don't have anything actually Secure Boot (TPM)
capable, to test all these variants.

What you really want to do, is be using the Popup
boot menu. This lists the devices detected during
the current BIOS POST sequence, and presents them in
a menu. If you have a USB stick with installable
OS or boot OS on it, it will be detected and show
up in the menu too. Cursor down to select
an item and boot from it.

For the CD/DVD, after you've done this, you still
have to be ready to "Press any key to boot from DVD",
which is presented as a separate step. If you don't
press a key, the opportunity to DVD "falls through"
and the next boot device is selected.

Windows 10 hard drive will easily reboot, if you
have Fast Start enabled or, you're coming out of
Hibernation. If Fast Start is enabled, this makes
it impossible to multiboot. Fast Start is a setting
in a Windows panel of some sort.

By using the popup boot, you *don't* have to fiddle
with that menu and add the optical drive. Popup boot
is temporary, and lasts for the one boot cycle. Perfect
for evaluating a LiveDVD once in a while.

*******

I hope the "Restore Defaults" works out for you.

As I'm real nervous about this NVRAM stuff.

It's when the "Restore Defaults" screen won't even
appear, you're in deep deep trouble.

The NVRAM is likely implemented as a write-able flash
segment in the BIOS chip. The CMOS RAM used by
a traditional BIOS, is too small to hold all those
NVRAM environment strings. Just one NVRAM environment
string could be stored in the CMOS RAM, and there might
be many of those strings.

My latest computer, has hardware flasher support. That
means, even if you pull the CPU out of the socket,
you can still plug in a USB stick and push a button on
the back of the computer, to update the BIOS flash chip.
No code is running, and the process is purely mechanical.
I've never needed to use this, but this is my
"get out of jail" card if I do something stupid
with the BIOS some day :-) That's an exclusive Asus feature.

Paul

Paul

unread,
Aug 4, 2018, 11:54:38 PM8/4/18
to
Boris wrote:
> Paul <nos...@needed.invalid> wrote in news:pk3a77$bo4$1...@dont-email.me:
> Good news.
>
> Last night, after posting, but before reading your post (thanks) this
> morning, I had already tried Restore Settings in the BIOS twice. Each
> time was unsuccessful, in that Windows Boot Manager still didn't show up
> in the Boot Sequence settings. Because it didn't show up, I thought it
> was gone forever, but I was puzzled as to why I could still boot into
> Windows 10 no problem.
>
> Then something very odd happened. I did a System Restore to three days
> earlier for other reasons. Restore went on for over an hour before I had
> to leave the house. When I got back three hours later, it was successful.
> Now I know System Restore does not touch BIOS settings, but I went back
> to the BIOS and there was Windows Boot Manager, and all other settings
> that I had changed, were back to default. I'm sure this was coincidental,
> and that the Restore Setting done earlier, which didn't take the first two
> reboots, finally took.
>
> So now I'm back to 'normal', or original as shipped BIOS settings.
>
> An F12 at power up give me this screen:
>
> https://postimg.cc/image/t85q95uaj/
>
> I read your reply, but couldn't get to the Dell link because Dell
> knowledge base is down 8/4 and 8/5 for maintenance. Just missed the
> maintenance window, but I suspect the article was about F2 and Restore
> Settings.
>
> I want to try again to be able to boot from CD/DVD, but am bothered (as
> are you) that the BIOS doesn't specify my particlar Toshiba optical drive.
> Rather, the BIOS simply describes it as "ODD Device = DVD+/-RW". The
> hard drive is specifically described...
>
> https://postimg.cc/image/am7k8ywu3/
>
> but on Boot Sequence screens, it's described as Internal HDD...
>
> https://postimg.cc/image/p2utn7txn/
>
> **********
>
> Moving on...
>
> In the BIOS Setup, I disabled Secure Boot, Enabled Legacy Option ROMs in
> Advanced Boot Options, Enabled Legacy in Boot List Options.
>
> I reboot, but *don't tap F12* (just curious). Message says:
>
> *********
>
> Intel UNDI, PXE-2.1 (build 083)
> Copyright Intel Corp.
> This productis covered by one or more...
> Realtek PCIe FE Family Controller Series v1.36 (11/26/14)
> PXE-E61: Media test failure, check cable
> PXE-M0F: Exiting PXE ROM.
> No Boot Device Found. Press any key to reboot the machine
>
> https://postimg.cc/image/r3ld8f86z/
>
> **********
>
> So I reboot and get this again, reboot and then get Dell SupportAssist
> doing a hardware check. Lower left-hand corner tells me that F2 will send
> me to BIOS Setup.
>
> https://postimg.cc/image/q2l4iyje3/
>
> Once done, all is ok, and I'm instructed to press Continue.
>
> I press Continue, but this time I *do tap F12*, and I get what I was
> expecting:
>
> LEGACY BOOT:
> Internal HDD
> CD/DVD/CD-RW Drive (not Toshiba 1234xxx, or DVD+/-RW as in BIOS
> specs) Onboard NIC
> UEFI BOOT:
> Windows Boot Manager
> UEFI: ST1000LM024 HN-M101MBB, Partition 1 (that's the 500 MB Healthy
> EFI System Partition)
> OTHER OPTIONS:
> BIOS Setup
> BIOS Flash Update
> Diagnostics
> Change Boot Mode Settings
>
> Here's a pic:
>
> https://postimg.cc/image/p2utn7txn/
>
> ************
>
> I chose CD/DVD/CD-RW Drive, the DVD light blinked green for a long, long
> time, and finally the DVD spun up, and Knoppix loaded.
>
> I thought I'd change the boot order and put CD/DVD/CD-RW Drive first (it
> was fourth) to speed things up.
>
> https://postimg.cc/image/k5h924mtn/
>
> It did speed things up quite a bit.
>
> *************
>
> Next, I wanted to see about booting into Win10. I rebooted, and from the
> selections above, I pressed Internal HDD. Message is the very short
> message received:
>
> "Selected boot device failed. Press any key to reboot the system." Not
> really surprised.
>
> Alright, I've got two choices remaining under UEFI BOOT.
>
> 1) ST1000LM024 HN-M101MBB, Partition 1 (but that's the 500 MB Healthy
> EFI System Partition, so I'm not going to select this)
>
> 2) Windows Boot Manager, which I select and it loads up Win10 just fine
>
> ***********
>
> I came away with the following thoughts:
>
> 1) Why doesn't LEGACY BOOT>Internal HDD, boot Win10? Where does that
> selection point?

An installation has boot management for one of the two standards.
You can install Win10 in legacy mode (by booting the DVD in legacy
and doing the install). Or, you can boot the DVD using the UEFI
item in popup boot, do the install, and UEFI stuff will get used
instead.

Legacy boot would have worked, if a legacy install had been
done first. Then that OS would have continued to support
legacy boot after that.

Note that a number of DVDs in Windows and Linux are Hybrid.
The optical discs show up *twice* in popup boot. And this
allows signaling to the installation process, which flavor
of install the user wants.

I don't really know what the split is on hard drives.
I think the one UEFI install I did, looked to be
pure UEFI.

>
> 2) Instead, Windows Boot Manager boots Win10

A UEFI BIOS sniffs this stuff, and in some BIOS, there is
even a labeled item for Windows 10 (making the coupling
or sniffing capability that much stronger). In some
cases, this even leads to the machine booting on its
own, without consulting the user at all (and it's not
due to Fast Boot either).

It's not clear when stuff like that happens, how the
control logic is bypassing the user step. On older
computers, we would always assume when the wrong
drive booted, that there was hardware trouble with
the actual desired drive, and that's why the BIOS
stepped over it. But on newer systems, it's almost
like the user isn't in complete control.

>
> 3) I miss the old setting the BIOS to look to optical drive first, and
> powering up, and if there's a cd/dvd loaded, it loads up, if not, the OS
> loads up

That hasn't disappeared entirely.

I have legacy BIOS machines which offer full control
of boot order on pools of storage devices. On those,
I would put my single optical drive first, then if
there is media in the tray, it will attempt to boot from it.
If I don't "press any key to boot" when that prompt
shows up, it falls through and selects an item from
the second group (a hard drive).

>
> 4) This is the first time I've really explored a UEFI BIOS. It doesn't
> seem to have as many options as the older BIOSs

This varies. For example, the DRAM timing page on my
UEFI machine, is chock full of settings, and scrolls
down for three or four pages worth.

>
> 5) In Add Boot Options,why wasn't there a path for the CD/DVD?

It's an over-reliance on NVRAM strings, and not enough
thinking by the developers, about what customers
really need. The actual code may indeed be using
the NVRAM strings (when a device "registers", it's
string is stored in the table, and then it
should have showed up for you to select).

>
> 6) Why, if in Boot List Options, I disable UEFI and enable Legacy, UEFI,
> along with Legacy, show up when I tap F12?

Your two choices are UEFI or UEFI+CSM.

It is, after all, a UEFI BIOS and doesn't
really have a pure legacy code at all. And
around the year 2020 or so, the CSM module
will get removed, leaving only UEFI mode.

>
> 7) I can explore the UEFI BIOS more, because there's always Restore
> Settings

Maybe. UEFI still makes me nervous. You can actually
fiddle with it from the OS level, which should make
you even more nervous. In one case, brickage from
doing that was possible (on an early generation
of UEFI).
>
> 8) I intuitively understand what is going on with the UEFI
>
> 8) I could really screw things up working on intuition
>
> Thanks for reading this far.

The cynics on the Internet, think this is a scheme cooked
up to lock Windows into the platform. And they're probably
right, because it doesn't have a lot of other
reasons to exist. I don't consider I have any
additional functions I didn't have before.
The old computer booted. The new computer booted.
Does someone deserve a prize ? The screen is pretty.
Is that important ? I'll take Courier font any day
in an interface, if I get more functions as a result.
I don't need glassy smooth BIOS screens, to enjoy my day.

Paul

Paul

unread,
Aug 5, 2018, 12:05:26 AM8/5/18
to
Boris wrote:
> Boris <nos...@nospam.invalid> wrote in
> news:XnsA934CBA8CA881n...@85.214.115.223:
>
> Great big snip
>
>
>> Moving on...
>>
>> In the BIOS Setup, I disabled Secure Boot, Enabled Legacy Option ROMs in
>> Advanced Boot Options, Enabled Legacy in Boot List Options.
>>
>> I reboot, but *don't tap F12* (just curious). Message says:
>>
>> *********
>>
>> Intel UNDI, PXE-2.1 (build 083)
>> Copyright Intel Corp.
>> This productis covered by one or more...
>> Realtek PCIe FE Family Controller Series v1.36 (11/26/14)
>> PXE-E61: Media test failure, check cable
>> PXE-M0F: Exiting PXE ROM.
>> No Boot Device Found. Press any key to reboot the machine
>>
>> https://postimg.cc/image/r3ld8f86z/
>>
>> **********
>
> I should add that when I got the above message about the NIC failing the
> test, the boot order was still set to:
>
> Diskette Drive
> Internal HDD
> USB Storage Device
> CD/DVD/CD-RW Drive
> Onboard NIC
>
> (but why did it pass up CD/DVD/CD-RW Drive?)
>
> Another great big snip

Did it decide you didn't actually have a
"CD/DVD/CD-RW Drive" ? Is anything registering
in that section ? Does that option work now at all ?

Removable media drives shouldn't be that far
down in the order. You want something like

diskette drive
optical drive
USB Storage
Hard drive
Onboard NIC (PXE)

The first two get skipped if no media is inserted.

Normally, there could be an entry where the
disable for the RealTek NIC is located, to
prevent PXE from being used. Once you do that,
the BIOS will stop and present a simpler message
that says no boot device was found. Rather than
PXE sitting there spinning its wheels pretending
eventually it will be booting.

Paul
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