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larandjohnson's avatar
larandjohnson
Copper Contributor
Mar 11, 2026

Windows 11 Insider Preview Feature Update (26220.7961)

Windows 11 Insider Preview Feature Update (26220.7961) is not installing, 2 Microsoft Tech tried and could not fix it -  the 2 techs and received the error on windows 11

update system reserve partition

 

1 Reply

  • hortonchipy's avatar
    hortonchipy
    Copper Contributor
    Apr 27, 2026

    This update usually fails when the System Reserved Partition is too small or not properly configured. Since even Microsoft techs couldn’t fix it, it’s most likely storage/partition related, not a normal update bug.

    Try this:

    Check System Reserved Partition size
    It should be at least 500MB–1GB free. If it’s around 100–350MB, Windows 11 Insider builds like 26220.7961 often fail.

    How to confirm
    Open Disk Management
    Look for “System Reserved” or EFI partition
    Check free space

    Fix options

    Clean up partition
    Remove old recovery files or unused boot files (safe only if you know what you’re deleting)
    Extend partition (best fix)
    Use Disk Management or third-party tool to increase System Reserved size to at least 500MB+
    Alternative workaround
    Disconnect extra drives
    Run update again after restart
    Sometimes installer picks wrong boot partition when multiple drives exist
    Last option
    In-place repair install of Windows 11, then retry Insider update