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How To Resolve the “Access Is Denied” Error When Running Bootrec /Fixboot

February 11, 2026 4 minuten lezen Updated: February 11, 2026

Getting that “Bootrec /FixBoot Access Is Denied” error is a real pain, especially if you’re poking around trying to repair your Windows bootloader. The thing is, on UEFI systems, Windows doesn’t quite handle this command the same way as with older BIOS setups, because the EFI System Partition (ESP) is kind of hidden and unmounted by default. So, when FixBoot tries to write to it, it just hits a wall with an “Access Denied” error. Frustrating, right? But there’s a workaround that’s worth trying, especially if you’re stuck and can’t boot into Windows normally. It involves manually mounting that EFI partition using diskpart, then rerunning some commands or using BCDBoot to rebuild the boot files. It’s kind of a hassle, but it works sometimes when other fixes fail. Plus, for some Windows versions like 1707, 1709, or 1803, this is *more* common, so if you’re on those, be prepared for extra troubleshooting.

How to Fix “Access Denied” When Running Bootrec /FixBoot on UEFI

Using Diskpart to Mount the EFI System Partition

This method helps because FixBoot can’t punch through the EFI partition if it’s not mounted. By assigning a drive letter to the ESP, you give Windows a location to work with. Here’s how it’s done:

  • Boot into your WinRE environment—go to Troubleshoot > Advanced options > Command Prompt.
  • First, identify which disk your Windows is installed on: diskpart
  • List all disks: list disk. Find your primary disk (usually Disk 0), then select it with: sel disk 0. On some setups, if your disk has a small size (~128 GB or 256 GB), it’s probably your main drive.
  • Next, list all volumes to find the EFI partition: list vol. Look for the volume labeled as System or FAT32, around 100MB-200MB in size. It might be marked as System and Boot. The volume number might be 2 or 3.
  • Select that volume: sel vol 2 (replace 2 with your volume number if different).
  • Assign it a drive letter—say R:—using: assign letter=R. This is necessary so Windows can work with it.
  • Type exit to leave diskpart.

Now, with the EFI partition mounted, you can attempt to repair boot files again. Running bootrec /FixBoot might work now, but if not, here’s the alternate magic trick:

Use BCDBoot to Rebuild Boot Files

  • Navigate to the EFI folder: cd /d R:\EFI\Microsoft\Boot\. If that path isn’t found, try these alternatives:
    • cd /d R:\Boot\
    • cd /d R:\ESD\Windows\EFI\Microsoft\Boot\
  • Run this command to copy the boot files from your Windows installation: bcdboot C:\Windows /s R: /f UEFI. Make sure to replace C:\Windows with your actual Windows directory if it’s different. This command rebuilds the BCD (Boot Configuration Data) and copies all necessary files to the EFI partition.
  • Optionally, backup your existing BCD first: ren BCD BCD.bak
  • Then recreate a new BCD store: Bcdboot C:\Windows /s R: /f UEFI.
  • Finally, type exit and restart the machine. Hopefully, your system can boot again without the “Access Denied” hiccup.

One thing to keep in mind: sometimes, Windows wants a bit more coaxing. The EFI partition can be stubborn, and on some setups, the commands might need slight tweaks. But hey, it’s often enough to get things rolling again. And yes, on some machines, the process might be a tad flaky—like, it works randomly, then not, then works again. Because of course, Windows has to make it harder than necessary.

When All Else Fails: Delete EFI and Use Automatic Repair

If mounting and manually fixing the EFI partition doesn’t help, another approach is to wipe it out and let Windows try to restore itself with its automatic tools. First, create a bootable Windows 10/11 media (preferably from a version like 1703, since it tends to be a bit more forgiving).Then boot into recovery mode, and do the following:

  • Launch Command Prompt again.
  • Use diskpart to delete the EFI partition:
    • diskpart
    • list disk
    • Select your drive with: sel disk 0
    • List volumes: list vol
    • Find and select the EFI volume: sel vol 2 (or your volume’s number)
    • Delete it: delete volume
  • Exit diskpart (exit) and then run the Startup Repair tool from the recovery menu. This process sometimes rebuilds the EFI partition from scratch, fixing underlying corruptions.

This approach is kind of drastic, but if the EFI partition was corrupt or misconfigured, it might just fix the root cause. Just a heads-up—wiping partitions can be risky, so be sure you’ve got backups if possible. After repair, restart and see if Windows boots normally.

Final thoughts

Sometimes these EFI boot issues pop up unexpectedly, especially after Windows updates or rogue disk operations. The key takeaway? Mounting that EFI partition manually and running BCDBoot or fixing the BCD directly often unlocks the boot process. It’s not always crystal clear, and on some setups, a bit of trial and error is needed. But in most cases, this method at least gives a fighting chance to fix things without a complete OS reinstall. Fingers crossed this helps someone get back on track without pulling too much hair out.

Summary

  • Mount EFI partition manually using diskpart to assign a drive letter.
  • Use BCDBoot to rebuild or copy boot files if FixBoot fails.
  • If needed, delete the EFI partition and use Automatic Repair to restore system files.
  • Be aware this process can be flaky depending on your hardware and Windows version.

Wrap-up

Getting rid of the “Access Is Denied” error on UEFI can be a bit of an adventure, but with patience and the right commands, it’s usually solvable. Just remember to be careful with partition operations—losing data is not fun. In most cases, manually mounting the EFI partition and using BCDBoot gives you a shot at fixing things without starting from scratch. Hope this cut some time off your troubleshooting grind — good luck out there.