Solved what does turning the BootDeviceFlag to 0x14 really do when booting from a device plugged into a USB 3.0 port?


T

trinhanhduc

Member
Local time
2:49 AM
Posts
7
OS
Windows 10
Like the title said, I kept seeing others getting the inaccessible_boot_device error when installing windows on a removable media and the only fix to this issue is to change the value of BootDeviceFlags. What does this do and why am I still be able to boot Hirenboot cd pe and windows installer from a USB device plugged into a USB 3.0 port?
 

My Computer

System One

  • OS
    Windows 10
    Computer type
    PC/Desktop
    Manufacturer/Model
    DELL
    CPU
    11th Gen Intel(R) Core(TM) i7-1165G7 @ 2.80GHz
    Motherboard
    DELL 0NX5H3
    Memory
    8 GBytes
    Graphics Card(s)
    Intel Iris Xe Graphics, NVIDIA GeForce MX330
    Hard Drives
    PM991a NVMe Samsung 512GB
Except for Windows To Go, Windows is not designed to run from a removable or network mounted device, because it can be unexpectedly disconnected from the system. You can force the BootDeviceFlag to have Windows ignore this restriction.

Windows ISO and the various USB repair tools boot from WinPE, which is designed to copy itself to a RAM disk in memory. So it doesn't care if you unexpectedly unplug the device after booting up. WinPE is a lightweight, stripped down version of Windows. A full Windows would get data consistency errors if you unplugged the storage device while it's running.
 
Last edited:

My Computer

System One

  • OS
    Windows 7
garlin said:
Except for Windows To Go, Windows is not designed to run from a removable or network mounted device, because it can be unexpectedly disconnected from the system. You can force the BootDeviceFlag to have Windows ignore this restriction.

Windows ISO and the various USB repair tools boot from WinPE, which is designed to copy itself to a RAM disk in memory. So it doesn't care if you unexpectedly unplug the device after booting up. WinPE is a lightweight, stripped down version of Windows. A full Windows would get data consistency errors if you unplugged the storage device while it's running.
Click to expand...
Then why don't I get the inaccessible boot device error when booting from USB 3.0 USB, I'm just curious
 

My Computer

System One

  • OS
    Windows 10
    Computer type
    PC/Desktop
    Manufacturer/Model
    DELL
    CPU
    11th Gen Intel(R) Core(TM) i7-1165G7 @ 2.80GHz
    Motherboard
    DELL 0NX5H3
    Memory
    8 GBytes
    Graphics Card(s)
    Intel Iris Xe Graphics, NVIDIA GeForce MX330
    Hard Drives
    PM991a NVMe Samsung 512GB
The Windows Installer, Windows PE, Hirens and other Boot disks are not the Microsoft Windows Operating Systems
The Windows OS is not designed to run from a USB drive unless you running Windows to Go
It would be far too slow running even at USB 3.3 speed
 

My Computer

System One

  • OS
    Windows 11 Pro Insider 64 bit 25H2 26200.5742
    Computer type
    PC/Desktop
    Manufacturer/Model
    Gigabyte Z390 UD
    CPU
    Intel Core i7 9700K 3.60
    Motherboard
    Gigabyte Z390 UD
    Memory
    16 GB
    Graphics Card(s)
    nVidia GEForce RTX 2060 Super
    Sound Card
    onboard
    Monitor(s) Displays
    Two 27" Dell 4K monitors
    Screen Resolution
    3840 x 2160
    Hard Drives
    M.2 NVME SSD, 500 GB; Two 2TB Mechanical HDD's
    PSU
    850w PSU
    Case
    Cyberpower PC
    Cooling
    Water cooled
    Keyboard
    Backlit Cyberpower gaming keyboard
    Mouse
    Backlit Cyberpower gaming mouse
    Internet Speed
    1 GB mbps
    Browser
    Brave
    Antivirus
    Windows Security
You must log in or register to reply here.

Similar threads

Solved Wireless USB dongle temporarily disconnects when connecting flash drive to USB 3.0 port
Replies
6
Views
3K
spapakons
spapakons

Latest Support Threads

Latest Tutorials

Back
Top Bottom