Fix BOOTMGR is compressed - Windows 10 startup error

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If when you boot your Windows 10 device, just your computer fails to boot and y'all only see a black screen with the bulletin BOOTMGR is compressed, Printing Ctrl+Alt+Del to restart, then this post is likely to assistance you lot.

File compression is a feature that allows PC users to subtract the size of files, folders, and programs, and reduce deejay space usage. Yet, since the organisation boot sector lawmaking lacks the power to decompress files by itself, the BOOTMGR file, which is a key role of the booting process, should not be compressed, otherwise, you'll encounter this error on Windows 10 startup.

BOOTMGR is compressed

If you're faced with this issue, you can try our recommended solutions below in no particular order and see if that helps to resolve the outcome.

Run Startup Repair
Rebuild Boot Configuration Data (BCD) file
Manually update the BOOTMGR File
Decompress drive.

Let's take a look at the description of the process involved apropos each of the listed solutions.

i] Run Startup Repair

Since this BOOTMGR is compressed error is preventing your Windows 10 system from startup and boot fully to the desktop, the first logical step to take is to, perform Windows x Startup Repair. Run the Startup Repair three different times, because sometimes it takes iii runs to fix it. If this does not fix your trouble move on to the adjacent pick.

2] Rebuild Boot Configuration Information (BCD) file

This solution requires y'all to rebuild the Kick Configuration Data (BCD).

iii] Manually update the BOOTMGR file

Since the boot error is oftentimes caused past a compressed BOOTMGR file, replacing the file is ofttimes a good and effective solution.

To manually update the BOOTMGR file, do the following:

Boot interrupt Windows 10 by starting your PC and as soon every bit you see the Windows logo; press and agree the ability push button to force a shutdown. Repeat this 2-4 times and Windows will open the Advanced Startup Options carte for you.

Alternatively, if available, yous tin employ the Windows ten installation media to kick your PC into the Advanced Startup Options menu.

At the Advanced Startup Options screen, select Advanced Options.
Select Troubleshoot.
Under Advanced options screen, select Command Prompt.
Next, type cd\ and hit Enter.
At present, blazonC: and hitting Enter.
Side by side, type in the command below and hit Enter:

bcdboot C:\Windows /s D:\

In one case the command executes, restart your computer and run across if it boots successfully without the upshot at paw. Otherwise, try the next solution.

4] Decompress/Uncompress drive

Since this error is often caused past a compressed hard drive, information technology is possible to fix it past decompressing or uncompressing the system drive.

To decompress/uncompress the drive, do the following:

Boot into Advanced Startup Options using whatever of the methods in Solution 3 above.
Admission Command Prompt and change to the C directory equally shown higher up.
In the CMD prompt, type the command below and hit Enter:

compact /u /southward /i *.*

Once the control executes, restart the reckoner. The issue should be resolved now.

Hope this helps!

Related mail service: Fix Bootmgr is Missing error in Windows x.

Obinna Onwusobalu, has studied Information & Communication Engineering and is a great follower of the Windows ecosystem. He runs a computer software clinic. He says it's best practise to create a System Restore Point earlier making whatsoever changes to your PC.