Where is the log for Windows 11 failed upgrades ?

Todd Chester 646 Reputation points

Hi All,

Windows 11-21H2

I am trying to upgrade to 22H2. After going through all the motions, I get rolled back with "Installation failed in SAFE_OS phase with an error during BOOT operation 0xC1900101 0x20017" error.

Where is the log file for me to look up what crashed?


Which begs the question, why is it save to run 21H2 and not 22H2?

Windows 11
Windows 11
A Microsoft operating system designed for productivity, creativity, and ease of use.
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  1. Todd Chester 646 Reputation points

    Found it:


    C:\$Windows.~BT\Sources\Panther: File named Setupact.log records actions in the downlevel and SafeOS phase. As the log can be very large, setup also creates a file named “Setuperr.log” that only has information about the errors encountered by the Setup to narrow the source of the problem.

    And from the same article:

    Error Code Troubleshooting
    C1900101-20017 A driver has caused an illegal operation. Make sure all unnecessary devices are disconnected except the keyboard and mouse.Remove any 3rd party anti-virus.Make sure BIOS firmware is updated on the motherboard.

    Now to figure out what driver is causing it.

  2. Limitless Technology 39,436 Reputation points


    If you're using a RAID or SSD controller for storage, you may find that the driver is not compatible with 22H2. Hence why the installation fails. You can try connecting your storage to a standard SATA connection for the duration of the installation and then swap it back once you have installed the updated drivers from within 22H2.


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  3. Todd Chester 646 Reputation points

    Host = Fedora 36
    Hypervisor = qemu-kvm-6.2.0-15.fc36.x86_6

    It is already on sata. Dang!

    <disk type="file" device="disk">
    <driver name="qemu" type="qcow2"/>
    <source file="/home/kvm/KVM-W11.qcow2"/>
    <target dev="sda" bus="sata"/>
    <boot order="2"/>
    <address type="drive" controller="0" bus="0" target="0" unit="0"/>


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