here's my situation: I had an HDD with Windows 8 installed (UEFI mode). I bought a SSD and wanted to do a clean install of Windows, so I thought that disabling the HDD and leaving the SSD as the only drive when installing was the right procedure to install the boot manager on the SSD.

Unfortunately, after I plugged the HDD back in, the computer won't boot unless I select from the BIOS directly the SSD as the boot device. I guess the problem is that I have two Windows Boot Managers on two separate drives and they conflict. How would I solve this problem (excluding a format of the HDD, because I need to access data on the old Windows partition and, ideally, I would like to be able to boot that partition)?

  • You need to list both installation in your boot loader then have one choice be the default. There are dozens upon dozens of questions here on how to do that.
    – Ramhound
    Oct 22 '13 at 14:51
  • My problem is more specific. I have two boot managers, one on each drive, and the one on the older drive starts but fails to boot because of some conflict with the other loader Oct 22 '13 at 15:48
  • Lots of people do what you describe without an issue. If the SSD installation was just done, I would just install Windows 8.0, with the hdd plugged in so the Windows installation can see all devices.
    – Ramhound
    Oct 22 '13 at 16:07

Assuming you have both Windows installed to GPT style disks with UEFI boot.

I think you cannot use one boot manager to dual boot one Windows the UEFI way, the other the BIOS way. Only 64-bit Windows 7/8 can boot UEFI way.

The easiest way would be to set your SSD as first disk in firmware.

Boot - you will get to new Windows installation.

In explorer see drive letter of other Windows (on HDD) assume it is H:

Open elevated(admin) command prompt (WinKey+X and select)

use following command:

bcdboot H:\windows

After reboot you will have a dual-boot choice where Win on HDD will be default.

To change boot order you could use Visual BCD Editor (reorder the two loader entries by editing DisplayOrder element of {bootmgr}

Note 1: Ignore message that BCD has changed when Visual BCD starts.

Note 2: A loader for EFI has following path - "\windows\system32\winload.EFI"

Note 3: Windows Boot manager for UEFI (and also other non-Windows OS boot managers) reside on a special partition called "EFI System Partition"(ESP) which is hidden and cannot be viewed in Explorer but can be listed using "dir" command after mapping system partition with "mountvol" command. The "system" BCD is also on ESP.

  • 3
    Thank you for you answer. Actually my problem was that the installation of Windows on the SSD was done using the legacy BIOS mode, and the disk was partitioned using MBR. That probably created the conflict with the UEFI windows boot manager. I reinstalled Windows for other reasons and this time I made sure that the disk was partitioned using GPT and that it was using UEFI. Now I can dual boot. I used your answer to make sure that the boot manager was on the SSD (better performance) so thank you very much! Oct 26 '13 at 8:27

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