Windows Boot Manager - Boot Selection Failed

[ZaphodB]

Okay...

A bit of background history first to set the scene...

WINDOWS 7 HP SP2 on a 2TB HDD. This was cloned onto a 5TB HDD in February 2020. Both 2TB and 5TB drives were bootable (as the 5TB was a clone of the 2TB).

I have been using the 5TB drive until recently when I decided to upgrade the boot drive to a SSD.

I made sure that all files since February had been copied to the 2TB disk when I bought and installed Win 10 Pro to a 240GB SSD. This was a CLEAN INSTALL to a brand-new SSD - not an upgrade.

So, to be clear, I had two HDDs (a 2TB and a 5TB) that had identical contents (files/folders/documents/pics etc) and both were bootable.

This is when the problems started.

The 240GB SSD boots happily into Win 10 Pro. That isn't the issue (at present), hastily touches wood.

I have been happily swapping between 5TB, 2TB and SSD in preparation for turning 5TB drive into a purely data drive and booting off the Win 10 SSD. When swapping between HDDs, I made sure that only one bootable drive was connected to the motherboard at any one time.

Yesterday, Friday 26th June, the 5TB drive reported the following ...

WINDOWS BOOT MANAGER

Boot selection failed because a required device is inaccessible.

Status 0xc000000e

I got nowhere with the 5TB drive - it was formatted under the MBR scheme and, as such, only 2TB was accessible to Windows. This is one reason why I decided to upgrade to a SSD for the boot drive and use the 5TB as a data drive (with a physically separate HDD as a backup for files and folders).

The 5TB drive now appears to Windows as a 561GB drive and nothing (so far) has been able to restore either the 2TB partition or the whole 5TB - even converting the drive to the GPT scheme.

I have tried formatting this drive to no avail - still only 561Gb visible and accessible and (presumably because of the formatting) the data contained on this drive has gone.

- end of 'background' history -

Anyhow, to the main thrust of this question.

I just swapped from the SSD back to the 2TB bootable Windows 7 HDD and I've got the same message:

WINDOWS BOOT MANAGER

Boot selection failed because a required device is inaccessible.

Status 0xc000000e

So now both the 5TB and 2TB disks are saying the same thing and I can't boot from either disk! The 5TB not surprising really as it has been reformatted!

With the 2TB disk, I have tried a STARTUP REPAIR using the OEM's Windows 7 disk.

Windows reported that there were some errors on the disk, tried to fix them, and when finished, told me that everything had been fixed (looked at the log and all issues said fixed with error code zero).

However, the drive STILL WON'T BOOT.

I still get the same "Boot selection failed ..." message.

Trying Startup Repair again - this time looking at System restore.

What I don't get is that when booting it says that the boot device is inaccessible, yet when Startup Repair runs, it finds the Windows Installation with no problems.

How can I get past this and have access to my 2TB drive again (so that I can recover all of the files and documents stored on it)?

Thanks in anticipation,

Zaph

 

[ZaphodB]

After a spot of Googling, it looks like I have to

a) Check in BIOS to see that the HDD Access Mode hasn't been changed (options are IDE/SATA/AHCI/RAID) and try changing this back to the original setting (if it has been altered)

If it hasn't been altered ...

b) boot from the CD/DVD into the Windows Recovery Environment, go to a commend prompt and type in:

'bcdedit' which will display the values for Windows Boot Manager. If device is listed as 'unknown' type in the following commands:

• bcdedit set {DEFAULT.EN_US} device partition=c:

• bcdedit set {DEFAULT.EN_US} osdevice partition=c:

• bcdedit set {BOOTMGR.EN_US} device partition=c:

Other things to try ...

Boot from the CD/DVD into the Windows Recovery Environment, go to a commend prompt and type in:

• Bootrec.exe /fixmbr

• Bootrec.exe /fixboot (and possibly)

• Bootrec.exe /rebuildBCD

However, another source said the following ...

"In order to completely rebuild the BCD Store, input the following commands at the Windows RE Command Prompt ..."

• bcdedit/export C:\BCD_Backup

• c:

• cd boot

• attrib bcd -s -h -r

• ren c:\boot\bcd bcd.old

• Bootrec\RebulidBcd

Yet another source said ...

From a Windows RE Command Prompt, start 'diskpart' and examine the partitions to see if the active partition (where the boot files are) is a separate partition.

NOTE: If using the Recovery CD, C: is mapped to the active (System Reserved) partition and D: is mapped to the partition where Windows is installed.

a) If this is the case,run the following command to fix the BCD

• bcdboot d:<Windows /s c:

b) If you only have one partition (which should be active) when fixing is done with, type in:

• bcdboot c:<Windows s/ c:

Most of the above is for my reference (save having to trawl the web again).

Comments anyone?

At the moment, the whole 2TB drive is accessible through a Linux Live CD - so I can recover documents/files/photos etc (however the My Documents folder alone has 53527 items and is 368.1GB in size)!

Zaph

 

[iko22]

...



Yesterday, Friday 26th June, the 5TB drive reported the following ...

WINDOWS BOOT MANAGER

Boot selection failed because a required device is inaccessible.


Thanks in anticipation,

Zaph

Boot from the CD/DVD into the Windows Recovery Environment, go to a commend prompt and type in:

• Bootrec.exe /fixmbr

• Bootrec.exe /fixboot (and possibly)

• Bootrec.exe /rebuildBCD

However, another source said the following ...

"In order to completely rebuild the BCD Store, input the following commands at the Windows RE Command Prompt ..."

• bcdedit/export C:\BCD_Backup

• c:

• cd boot

• attrib bcd -s -h -r

• ren c:\boot\bcd bcd.old

• Bootrec\RebulidBcd

Yet another source said ...

From a Windows RE Command Prompt, start 'diskpart' and examine the partitions to see if the active partition (where the boot files are) is a separate partition.

NOTE: If using the Recovery CD, C: is mapped to the active (System Reserved) partition and D: is mapped to the partition where Windows is installed.


Comments anyone?

At the moment, the whole 2TB drive is accessible through a Linux Live CD - so I can recover documents/files/photos etc (however the My Documents folder alone has 53527 items and is 368.1GB in size)!

Zaph

This looks the best match solution to the problem.

Also use bootrec /scanos to identify windows 7 installation, before and after you make any changes.

 

[dg1261]

The 561 GB figure is easily explained. Because it uses a 32-bit sector register, the MBR partition table can only handle up to about 2.2 TB (decimal), or 2048 GiB (binary gigabytes). After it reaches that value, the counters roll over back to zero and start counting up again. Your disk may be marketed as 5 decimal TBs, but that's actually 4656.6 GiB. And thus: 4656.6 - 2048 - 2048 = 560.6 GiB.

That's why you really shouldn't use disks larger than 2 TB with a MBR partition layout.

As for the Stop error, it might help to have a little more info. Did the problems begin immediately after installing 10 on the SSD? If so, perhaps you can point to that as a cause and effect.

Might the other disk(s) have been in the system when that was taking place? If so, the 10 setup routine may have trashed the startup configs on the other disks such that, when you subsequently tried to revert to 2TB-only or 5TB-only, they could no longer start by themselves.

However, if the other disks were not in the system when 10 was installed, then you should be able to rule out a corrupted BCD or System Reserved partition, and all that BCD advice should be superfluous and you'll need to look elsewhere.

But that would not rule out a change in the BIOS configuration. If, for instance, you had a IDE/ATA Win7 install on the 2TB disk and Win10 changed the BIOS mode to AHCI for the SSD, Win7 on the 2TB disk would fail to boot -- in fact, IIRC, exactly with the ..0E Stop error you've received.

Your second post acknowledges the advice to, "Check in BIOS to see that the HDD Access Mode hasn't been changed", but you didn't indicate whether you did so. All of those BCD commands are getting ahead of yourself, and will do not good, if you're not sure what BIOS mode Win7 was installed under.

If you haven't messed with anything on the 2TB disk yet, I would suggest first putting it back in as the only attached disk, then try cycling through each BIOS setting (IDE/SATA/AHCI/RAID) and seeing if one of them will allow Win7 to boot.

Don't forget you'll need to set it back before the SSD will boot again.

 

[ZaphodB]

The 561 GB figure is easily explained. Because it uses a 32-bit sector register, the MBR partition table can only handle up to about 2.2 TB (decimal), or 2048 GiB (binary gigabytes). After it reaches that value, the counters roll over back to zero and start counting up again. Your disk may be marketed as 5 decimal TBs, but that's actually 4656.6 GiB. And thus: 4656.6 - 2048 - 2048 = 560.6 GiB.

That's why you really shouldn't use disks larger than 2 TB with a MBR partition layout.

Hi dg1261, thanks for the info. This confirms what I've already found out in the past three days, plus the particular HDD (Toshiba X300 5TB) apparently is an 'Advanced Format' or 'AF' drive which does some clever translation to manage the space above 2TB - apparently in conjunction with a hardware interface in an external caddy - although it was supplied as an internal drive in a retail box and was marked as such.

As for the Stop error, it might help to have a little more info. Did the problems begin immediately after installing 10 on the SSD? If so, perhaps you can point to that as a cause and effect.

No. Sorry for the confusion. I had swapped over to the 5TB drive and got the stop error 0xc000000e. This was the only drive connected to the mobo via the internal SATA connections.

Might the other disk(s) have been in the system when that was taking place? If so, the 10 setup routine may have trashed the startup configs on the other disks such that, when you subsequently tried to revert to 2TB-only or 5TB-only, they could no longer start by themselves.

However, if the other disks were not in the system when 10 was installed, then you should be able to rule out a corrupted BCD or System Reserved partition, and all that BCD advice should be superfluous and you'll need to look elsewhere.

The 240GB SSD with the clean Win 10 install was the only disk attached to the PC when I installed Win 10.

But that would not rule out a change in the BIOS configuration. If, for instance, you had a IDE/ATA Win7 install on the 2TB disk and Win10 changed the BIOS mode to AHCI for the SSD, Win7 on the 2TB disk would fail to boot -- in fact, IIRC, exactly with the ..0E Stop error you've received.

AFAIK, both the 5TB and the 2TB disks that are now showing the 0xc000000e error were NOT in AHCI mode - is it possible that the SSD with the Win 10 install has 'flipped' the BIOS into AHCI mode? If so, this might explain things.

Your second post acknowledges the advice to, "Check in BIOS to see that the HDD Access Mode hasn't been changed", but you didn't indicate whether you did so.

Not yet done this. This is my next job!

All of those BCD commands are getting ahead of yourself, and will do not good, if you're not sure what BIOS mode Win7 was installed under.

If you haven't messed with anything on the 2TB disk yet, I would suggest first putting it back in as the only attached disk, then try cycling through each BIOS setting (IDE/SATA/AHCI/RAID) and seeing if one of them will allow Win7 to boot.

I'm loathe to do this at the moment because the 2TB disk contains all my historical data and is accessible through Linux if attached as an external USB drive. When I cloned the 2TB disk onto the 5TB disk in February (and I have copied the most recent data from the 5 onto the 2 just before this problem occurred), I then had two locations which contained my data. Having lost one (the 5) I'm going to get a large SD card and then ensure that all of the data off the 2TB is copied onto a different PC. I'll then try your suggestion.

Don't forget you'll need to set it back before the SSD will boot again.

Agreed! First thing is with the SSD attached, go into BIOS and note down all of the relevant settings!

Thanks for your suggestions. I'll update this thread in due course.

Kind regards

Zaph

 

[dg1261]

is it possible that the SSD with the Win 10 install has 'flipped' the BIOS into AHCI mode? If so, this might explain things.

That's what I'm suggesting.

Not yet done this. This is my next job!

I'm loathe to do this at the moment because the 2TB disk contains all my historical data and is accessible through Linux if attached as an external USB drive. When I cloned the 2TB disk onto the 5TB disk in February (and I have copied the most recent data from the 5 onto the 2 just before this problem occurred), I then had two locations which contained my data. Having lost one (the 5) I'm going to get a large SD card and then ensure that all of the data off the 2TB is copied onto a different PC. I'll then try your suggestion.

Simply flipping the BIOS AHCI mode shouldn't change anything on the hard disk (or SSD) so should be safe to test, but I understand your reticence if you're down to your last copy of irreplaceable data.

If your plan is to first backup your data to a different PC, you should be able to connect your 2TB disk directly to the other PC and copy your data in one step. You shouldn't need to do an intermediary step by copying to SD card.

The IDE/AHCI mode only affects what drivers need to be on the boot disk. It doesn't physically change anything on the disk, it only affects which drivers Windows must be configured to use when it boots. If Windows on the 2TB was setup to boot with IDE/ATA drivers, it will fail to boot if the BIOS is demanding AHCI drivers, and vice versa.

But the mode setting shouldn't affect whether the disk's data is accessible if booted by other means. That's why your linux boot CD can see and access the files on the hard disk, regardless. You should also find that your AHCI-mode Win10 can see the 2TB disk's files when connected in the external USB enclosure ... are you finding that's not the case?

As for the 5TB disk, Disk Management can convert it from MBR to GPT if there are no partitions on it. So first remove all partitions, convert it from MBR to GPT, then create one (or more) GPT partitions on it. It doesn't matter which PC you do this on.

Note you can use a GPT data disk even if your boot disk is MBR. Both disks do not need to be the same partitioning style. The only requirement is the boot disk's partitioning style must be consistent with the boot mode (Legacy/MBR vs UEFI/GPT).


Aside: I used to have a 1525 until it died about 5 yrs ago. I removed the DVD drive and used a drive bay adapter so I could install two hard drives internally. (The DVD drive was malfunctioning anyway, so I ditched it in lieu of an external USB DVD drive that could be safely stored away when not in use ... which was most of the time.) I had a 500GB SSD running Win7 in the main HDD bay, and a 2TB hard disk for data storage in the media/DVD bay.

 

[ZaphodB]

That's what I'm suggesting.

Interesting. That would explain things however.

Simply flipping the BIOS AHCI mode shouldn't change anything on the hard disk (or SSD) so should be safe to test, but I understand your reticence if you're down to your last copy of irreplaceable data.

If your plan is to first backup your data to a different PC, you should be able to connect your 2TB disk directly to the other PC and copy your data in one step. You shouldn't need to do an intermediary step by copying to SD card.

Currently, the 2TB HDD is connected to my laptop (running Win 7) and, using the Administrator account, I’m copying the ‘My Documents’ folder to the 960-odd GB of free space on that HDD.

In parallel with this, my desktop is currently sanitising the 5TB disk’s free space in readiness for transferring the documents from the 2TB disk (via the laptop’s HDD as an intermediary).

The IDE/AHCI mode only affects what drivers need to be on the boot disk. It doesn't physically change anything on the disk, it only affects which drivers Windows must be configured to use when it boots. If Windows on the 2TB was setup to boot with IDE/ATA drivers, it will fail to boot if the BIOS is demanding AHCI drivers, and vice versa.

Didn’t know that.

But the mode setting shouldn't affect whether the disk's data is accessible if booted by other means. That's why your linux boot CD can see and access the files on the hard disk, regardless. You should also find that your AHCI-mode Win10 can see the 2TB disk's files when connected in the external USB enclosure ... are you finding that's not the case?

Not yet tried that. Could save me a bunch of time!

That said, I’ll end up with the data in two physically separate disks - always a good idea!

As for the 5TB disk, Disk Management can convert it from MBR to GPT if there are no partitions on it. So first remove all partitions, convert it from MBR to GPT, then create one (or more) GPT partitions on it. It doesn't matter which PC you do this on.

Note you can use a GPT data disk even if your boot disk is MBR. Both disks do not need to be the same partitioning style. The only requirement is the boot disk's partitioning style must be consistent with the boot mode (Legacy/MBR vs UEFI/GPT).

Yep, I knew the bit in bold (one of the few things about this that I do know)! Currently my setup is Win 10 Pro on a 240GB SSD (MBR partitioning scheme) and the 5TB HDD for data using the GPT scheme so that I can see the full 5TB.

Aside: I used to have a 1525 until it died about 5 yrs ago. I removed the DVD drive and used a drive bay adapter so I could install two hard drives internally. (The DVD drive was malfunctioning anyway, so I ditched it in lieu of an external USB DVD drive that could be safely stored away when not in use ... which was most of the time.) I had a 500GB SSD running Win7 in the main HDD bay, and a 2TB hard disk for data storage in the media/DVD bay.

My 1525 came from my niece when the HDD went south. My brother-in-law gave it to me “If you can use it”, I put a new HDD in and put a legit copy of Win 7 on it and was back up and running very quickly. When the free Win 10 offer came up I upgraded (?!) the lappy to Win 10 to try it out to see what I thought.

A decent budget laptop - originally came with Vista, ran W7 without a problem and currently running Win 10 also without a problem. Only problem with it is the graphics (on-board) which is absolute pants!

Zaph

 

[Snick]

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EaseUS® Partition Master - Best partition manager software ...

AOMEI Partition Assistant - A Safe Partition Manager for ...

Free programs, I use both and recommend them & retains your data.

Snick