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My boot files and BCD are on E:, My windows files are on C:

When setting the BCD should the windows boot loader device and osdevice be C: or E:?

I already have an entry for Windows Boot Manager which has the parameter device partition=E:

I'm on 64bit Windows 8.1

Ajay
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Max
  • 151

3 Answers3

11

Max is not completely right in his own answer (23. dec 2013) to his own question.

The answer is that both (device + path) and (osdevice + systemroot) make up a whole.

a) (device + path) is the "complete file path" to Windows loader for Vista, Windows 7/8

  • usually "c:\windows\system32\winload.exe" (or extension .efi for UEFI boot).

b) (osdevice + systemroot) is the "complete directory path" to Windows directory

  • usually "c:\windows".

There is no need for path to boot manager (bootmgr) and BCD itself as they are established programmatically during initial load and execution of MBR and PBR (master and partition boot record) for BIOS booting. Both bootmgr and \Boot\BCD are on active partition on MBR style disk.

On GPT disks (using UEFI booting) boot manager and BCD are on ESP (EFI System Partition).

It is obvious that the path to BCD inside of BCD cannot be used when loading BCD for the first time (BCD is loaded by boot manager).

You can find information about how to fix boot BCD problems here.

snayob
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Both device and osdevice should point to the drive the OS is installed on, not the boot files.

If you have a single OS there is usually no need to change this.

Say you have another bootable Windows on another drive and want to add it to the current boot configuration data store.

You would set both device and osdevice to the drive-letter that other Windows is currently on (internally this will not be stored as a drive letter anyways)

Peter Hahndorf
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0

I'll answer my own question. The osdevice is what should be pointing to your os partition (seems obvious when it works doesnt it?)

The device parameter points to your boot bcd (which may be on a separate drive)

To check that in cmd use bootsect.exe /nt60 all /force which should show all your drives.

In addition, another helpful tip is if you do not have an ISO of Win 8 then you can download an evaluation version from technet. I wont post a link as im sure it will be invalid/dead by the time anyone sees this. A lot of laptops (especially netbooks) no longer come with them and there are no official ISOs like in the Win 7 days.

I hope this helps someone. It is very frustrating and most similar issues end up in a reformat from what i've googled.

Max
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