Windows 10: Failure to Boot Windows 10 with external USB HDD connected

This is being posted as an additional answer for a problem that a closed thread helped me solve: https://answers.microsoft.com/en-us/windows/forum/all/unable-to-boot-windows-10-with-external-hard-drive/bebed3d3-eddd-4132-b7bd-d5335945e981


I was having this issue with my laptop, where if the External USB drive 2tb Adata USB3, 1 NTFS partition was connected on boot, I would get the familiar 'failed to find operating system' greeting just after POST. Most times, when you have a USB drive connected on bootup and the computer fails to find the operating system, it is due to bios boot settings attempting to boot devices out of order, trying your USB device prior to your internal drive. I scoured the settings and this was not the case, but proceeded to disable all USB booting period as a troubleshooting step. Same result. I could start up my Windows 7 laptop with the same USB drive connected without issue with comparable bios settings fine, so it appears that it was not the BIOS doing the boot, but the Windows 10 Boot Loader attempting to start the incorrect drive. My system disk on this laptop is a single 1TBm-sata that was setup by windows 100mb system partition[ntfs], ~930GB C: drive[ntfs], 628mb Recovery Partition. Both system HDD and USB HDD are set to MBR, not GPT.


The fix I found was to remove the 'Active' bit that was set on the USB HDD. Since I wasn't booting or intending to boot from this disk on any of my systems, this was an acceptable fix.


Looking at the Boot configuration with BCDEdit, my entries refer to Boot Manager and Boot Loader as "\Device\HarddiskVolume1" and "partition=C:", respectively, instead of a unique ID like GPT would use. Does this mean that regardless of Bios boot order or boot settings of what devices to use, the Windows Boot Loader is victim to the order drives are recognized in the Bios period and thus the order windows assigns drive letters before it has a chance to read any registry settings later in the boot process? Is there a way with MBR to preciesly define the boot device in BCDEdit?


Hopefully this helps someone find the less sought after.

:)

 

Boot from external USB HDD

Hello!

Any laptop should be able to Be booted from an external HDD.

You can check this back accessing your BIOS and then checking if the BIOS gives you an option to boot from USB.

If that option is listed, then you're good to go!

 

Windows 10 USB boot

Hi there, am not a windows 10 expert. I have a pc in the bedroom on windows 10, I messed up the bootloader trying to fix the xp on that system.

System wont boot, trying to repair via win 10 usb installer.

Downloaded the media creation tool to install windows 10 installer on usb stick. Not compatible with a host of usb sticks I have. Tried the usb sticks that others use, but I think they use rufus; as the media creation tool by win 10 does not detect the usb stick.

So quick question, the win10 machine i am trying to repair the bootloader is a win7 upgraded to win10.
If i were to use the usb win10 installer to "repair installation" does the version of the iso downloaded via the media creation tool matter?

There is three options:
Windows 10
Windows 10 Home
Windows 10 N

Also is there a step by step instead of using rufus as I want to try an alternative method of creating a usb win 10 installer. Preferably with more compatibility.

System is a asus sabertooth 990 (r2?) with AMD phenom X 6.

Also is there any other software I can load onto the usb that can repair the bootloader easily?
That would be the ideal alternative. Thanks

 

External HDD/USB.

Hello.

I have an external HDD docking station connected to my PC thru USB.

Devine manager sees it. But Windows explorer does not.

Suggestions?