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Can't update Windows 11 due to System Reserved Partition Size

Anonymous
2025-01-12T15:39:49+00:00

I've been trying to update to Windows 11 from Windows 11 for a while now but keep getting the error 'Could not update the system reserved partition' error. My computer is a HP laptop Elitebook 360.

My System Reserved Partition (SRP) is 100MB (which seems small) and it is almost full.

Things I have tried:

  • Deleting Language folders and Fonts from the SRP, I managed to free up 15MB and the update got further than normal but still failed citing 'Updates are available, but we temporarily need some space to download. Let's clear some space by removing any files and apps that you don't need and we'll try again'. My hard drive has over 400GB free which should be more than enough. It didn't specify where it needed space. After this attempt the SRP is full again.
  • Using several disk partition tools to move or resize partitions. The Microsoft Reserved Partition is between C and the SRP so it won't let me increase the size of the SRP or move it. I can't resize the MRP at all. I've tried EaseUS, PartitionWizard, and AOMEI. AOMEI seems to have the option but it requires payment. I don't think I should pay £50 to update to windows 11!
  • Installing a fresh install using a USB boot version, this suffers from the same issue - could not update the SRP. I haven't yet tried deleting the fonts and language folders and then doing a fresh install from USB. I am going to try this next.

Questions: What size storage needs to be available in the SRP to update to Windows 11? Is there anyway I can increase the size of the SRP? There are HP system files filling up most of the SRP, can I delete them safely prior to a Windows update?

Windows for home | Windows 11 | Windows update

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  1. Ramesh Srinivasan 79,560 Reputation points Independent Advisor
    2025-01-12T16:13:25+00:00

    Hi Carolyn, This is Ramesh.

    The default size of the EFI partition is 100 MB. Deleting the HP BIOS image files from the EFI folder should free up substantial disk space in that volume.

    Please open an admin Command Prompt window (instead of PowerShell) and run these commands one by one:

    mountvol Y: /s

cd /d Y:\EFI\Microsoft\Boot\Fonts

del *.ttf

powershell -command "GCI Y:\  -File -Recurse | Sort Length -descending | Select FullName, Length -first 10"

dir Y:\

    Post the output here.

    Note: If you wish to resize the EFI partition (which will be a permanent fix for this issue), you can use AOMEI or a similar third-party tool. Please check out this thread, especially the last reply in that thread.

    https://answers.microsoft.com/en-us/windows/for...

    10+ people found this answer helpful.
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  2. Anonymous
    2025-05-15T12:49:42+00:00

    Could someone explain this to me like I was in Kindergarten? I am getting the system reserve partition error as well and I have no idea what an EFI file is or any of the other language used by those of you who are much smarter than myself.

    Some other comments explain the fix. Maybe this will simplify the instruction:

    1. Click your Windows start menu and type: CMD and click Run As Administrator. You will see a black Command Prompt window pop up.
    2. Enter the following commands 1 at a time, press enter after each:
    • mountvol Y: /s
    • cd /d Y:\EFI\Microsoft\Boot\Fonts
    • del *.ttf
    1. That's it. You've cleared unnecessary files from the system reserved partition which should allow you to upgrade Windows.
    2. Retry running the upgrade.

    In short, the issue is the system reserved partition is too small and not enough free space. Whoever installed Windows (HP/Lenovo/Dell) from the factory partitioned the system reserve too small, thus causing the issue. The partition contains the Windows Boot Manager and Boot Configuration Data (BCD). These are essential files used to start Windows. Essentially without this partition, Windows wouldn’t know how to load the operating system during boot-up. Recent Windows 11 Media now automatically size the partition to 260MB vs. 100MB, so folks who have fresh Windows Installs should never run into this issue. It's a shame Windows upgrades can't just automatically run the 'Fix' to clear up space.

    6 people found this answer helpful.
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  3. Anonymous
    2025-03-07T18:51:32+00:00

    Could someone explain this to me like I was in Kindergarten? I am getting the system reserve partition error as well and I have no idea what an EFI file is or any of the other language used by those of you who are much smarter than myself.

    6 people found this answer helpful.
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  4. Anonymous
    2025-01-12T18:23:45+00:00

    Thanks for your reply.

    Sadly the issue is worse. I tried step 1 from the other thread to create some unallocated space on my hard drive. This partially failed and now the computer won't boot at all. It gives me a black screen.

    I'm currently running HP system tests to see if that will fix the issue. Trying to install windows from the USB won't work either.

    3 people found this answer helpful.
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  5. Anonymous
    2025-01-20T22:32:39+00:00

    I have 100 MB of free space in my EFI partition, 731MB free in Recovery Partition and still can't install 24H update on my HP with Win 11 Pro. Any other advice or guidance? 

    2 people found this answer helpful.
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