Reasons why Microsoft does not support starting Windows from external drives

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Some of us like to install and carry Windows on USB drives. But these are scenarios that Microsoft does not support. It is not supported to boot Windows from external devices. Such facilities are not supported.

If you choose to install Windows on a USB drive, Flash Drive(UFD), ESATA drive, or Windows 7 Native Boot VHD on a USB/UFD drive, Microsoft does not support it.

The reasons why this option is not supported are listed in KB2485453:

January 2021 Update:

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  1. Activation problems.
  2. Possible problems with boot path support.
  3. You must deactivate the device’s write cover or click’Securely delete’ before removing the cable. If you do not, you may lose data.

However, there are some specialized products that support this type of scenario, namely installation on external disks :

  • Windows 7 Embedded supports this scenario
  • Microsoft Hyper-V Server 2008 R2 supports booting from a USB flash device (UFD). Starting Hyper-V Server 2008 R2 from a USB stick is only supported by OEMs.

Just so you know! 🙂

RECOMMENDED: Click here to troubleshoot Windows errors and optimize system performance

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