5 Easy Steps To Fix “BOOTMGR Is Compressed” Error

The error message “BOOTMGR is compressed  Press Ctrl+Alt+Del to restart” may appear when you start up your computer.

If you press Ctrl+Alt+Del that just restarts the computer and then displays the same error message again.

I saw this error recently on a customer’s computer and thought I’d share how to fix it – the error can affect Windows 10, 8, 7, Vista and XP computers.

What Is BOOTMGR?

BOOTMGR refers to the Boot Manager – an important Windows system file. If it is compressed, it can’t be used and Windows can’t start (boot up). The file must therefore first be uncompressed for Windows to be able to boot properly.

File compression used to be a good way to save hard drive space – back in the days when hard drives were maybe 2 or 20 GB in size…

However, modern drives offer hundreds (or thousands) of GB storage so there really is no need to compress files.

Why is BOOTMGR Compressed?

There are two likely reasons that it may have been compressed.

bootmgr is compressed
Bootmgr is Compressed error
  • 1. You installed a ‘Speed Booster’ or ‘System Optimizer’ type of program – perhaps one with grand claims of boosting performance and with a super duper registry cleaner thrown in… See ‘do I need a registry cleaner’ – the short answer is No.

Such a program often causes this problem by compressing the whole of the system partition (usually the C: drive) to save space – including the crucial BOOTMGR file. This is what happened in my customer’s case.

File compression (even when done properly) may slow down system performance anyway so it is a lousy thing for a ‘speed booster’ utility to do…

  • 2. You manually compressed the whole of the system partition (via the drive’s Properties window).

How To Fix BOOTMGR is Compressed Error

The fixes for Windows 10 and all earlier versions of Windows are very similar – they require you to recreate the BOOTMGR file.

Windows 10/8/7/Vista Fix

Boot into the System Recovery Options using the preinstalled Advanced Boot Options or a Windows installation/recovery DVD – see the illustrated tutorial at Sevenforums for instructions if required.

Select ‘Startup Repair’ and wait until the repair attempt completes. If successful you can then restart the computer and Windows may boot up normally.

If the repairs fail and/or the computer does not restart into Windows normally, proceed with the 5 step fix as follows:

Step 1
Boot into the System Recovery Options again but this time select ‘Command Prompt’ instead of Startup Repair – this will take you to a windows Command Prompt.

[Note: if using RAID for multiple hard drives you may not see your version of Windows listed in System Recovery Options, during the loading of the recovery process. In this case you would need to press ‘Load Drivers’ and browse to your RAID drivers so that your version of Windows can be listed.

Step 2
Type bootrec /fixmbr and press Enter.

Step 3
Type bootrec /fixboot and press Enter.

Step 4
Type bootrec /rebuildbcd and press Enter. Type Y and press Enter if asked to add the installation to the boot list:

Bootrec commands to fix Bootmgr is compressed
Bootrec commands

Step 5
Now type Exit and press Enter to restart the computer. The error message should not appear and Windows should start up normally.

Windows XP Fix

You will need to have a bootable XP installation CD available.

Step 1
Log into the Recovery Console command prompt by following steps A to F in my article on fixing ntldr. You should now be in the C:\Windows directory.

Step 2
Type fixmbr and press Enter. Press y to accept the warning and proceed:

fixmbr
Fixmbr

Step 3
Type fixboot and press Enter. Press y to to confirm and proceed:

fixboot
Fixboot

Step 4
Type Exit and press Enter to restart the computer.

Step 5
The error message should not appear and Windows should start up normally.

Alternative BOOTMGR Is Compressed Fix

This fix should not be required but, if for some reason the previous fixes failed to resolve the problem, you may need to decompress all files on the system partition manually.

  • Log into the System Recovery Options \ Command Prompt (Vista/Windows 7/8/10) or Recovery Console command prompt (XP).
  • Type compact /u /a c:\*.* and press Enter. The command may take a long time (hours) to complete on a very large drive – leave it until finished.
  • Once it finishes decompressing all files, type Exit and press Enter to restart the computer. The error message should not appear and Windows should start up normally.

Note: if your Windows system drive is not c: then change the c in the command to your drive letter e.g. d:\

What Does The Compact Command Do?

This command decompresses (/u) all files (*.*) on the c:\ drive including hidden and system files (/a).

Conclusion

Unfortunately Windows does nothing to prevent an ‘optimizing’ program (or a user) from compressing Bootmgr – even though it means that Windows will not boot…

However, this problem is relatively straightforward to fix and easy to avoid in future – don’t use system optimizing utilities that may compress the Windows system partition and don’t try to compress it manually.

171 thoughts on “5 Easy Steps To Fix “BOOTMGR Is Compressed” Error”

  1. I placed the dvd, change boot sequence and the the message “BOOTMGR IS COMPRESSED ” continues.
    Am i missing something?

    • It’s not booting from your DVD. The DVD must be a full windows installation disc – also check the BIOS boot order again, DVD must be first, ahead of hard drive. If both are correct it will boot from the DVD

  2. Hi
    Plse advise my laptop cannot open my bootmgr is compressed and if l press ctrl+alt+del to start.The system fails to start advise.

    Pk

    • Ctrl alt del should work but if it doesn’t you’ll have to just turn off (hold down power button for up to 10 seconds) and back on again – check BIOS is set to load from DVD if using recovery disc

  3. hi ray and Hafthor
    finally i have the problem resolved. as to make the story short, before i went to the cmd mode directly because there is no ‘Windows 7? listed in System Recovery Options then i cannot access to C:>.prompt. since ray mentioned “windows” sholud be appeared in the system recovery sindow, then i tried the load drivers button then the “window” appeared in the window. then type in the commands and finally all works.
    thank you all very much

    • It’s rare that you need to load drivers unless using RAID but that’s why I asked if you saw W7 listed – you beat me to the next step ;-)

      Thanks for posting your update and glad you got it sorted!

  4. thank you Hafthor for your reply.
    to be honest i am getting lost in the cmd prompt. i am in X:\windows\system32\, when i typed “bootrec.exe c:” enter, i got “repair critical disk structures. The following commands are supported…………” when i typed “bootrec c:/ fixmbr” enter, got the same message as above. as i stated in my previous message i cannot access hard disk C. still stuck in bootmgr problem.

    • @Oak – Hafthor is right, you’re stuck in X: which is the repair disc. Type C: then press Enter – does that take you to the C:\> prompt?

      If so, now follow the steps in the guide bootrec /fixmbr etc.

      If not, did you ever see your ‘Windows 7’ listed in System Recovery Options – during the loading of the recovery process (i.e. prior to the screen where you choose Startup Repair/Command Prompt option)?

  5. X: stands for you repair disc. When using command prompt you see first X: as your boot. Using commands as “bootrec.exe” I have always had to use “bootrec.exe c:”
    Same parameter with fixmbr.

    Wait for Roy to explain it better. Just trying my best :) Hope it helps.

  6. my hard disk had two partiions one is system resered(~100MB) and one is c when i used the windows 7 repair disk it only showed boot(X:) no c. command prompt is in x:\windows\system32\. type “bootrec /fixmbr” got “the system cannot find the path specified”. try “compact /u /a c:\*.* ” using x: instea c: got “compact” is not recongized” what should i do to fix this problem. thanks

  7. Hi Ron, I have Win 7 (not Win /) :). There is another parameter I was looking for and it´s “fixmbr”. Does it work the same as bootrec ?

    I had XP and this commands works the same.

    Keaboga. At some pages you can download xp cd. Just search. But as Ron say best to obtain a legal cd from friends.

    • Bootrec is just a tool, it needs a parameter to do anything.

      In XP you could just use the fixmbr command by itself but in Vista and W7 you need to use the bootrec tool with a parameter i.e. bootrec /fixmbr

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