Jump to content


Register a free account to unlock additional features at BleepingComputer.com
Welcome to BleepingComputer, a free community where people like yourself come together to discuss and learn how to use their computers. Using the site is easy and fun. As a guest, you can browse and view the various discussions in the forums, but can not create a new topic or reply to an existing one unless you are logged in. Other benefits of registering an account are subscribing to topics and forums, creating a blog, and having no ads shown anywhere on the site.

Click here to Register a free account now! or read our Welcome Guide to learn how to use this site.


How to fix MBR on Win 7 + 8-1 dual boot system

  • Please log in to reply
3 replies to this topic

#1 FredinBB


  • Members
  • 2 posts
  • Local time:09:55 AM

Posted 15 July 2018 - 02:21 AM

Hi there,


Black screen with blinking cursor on Windows 7 + Windows 8-1 Dual Boot laptop (Asus N75).   

Diagnostics indicate MBR problem.

Have genuine Windows 7 install disk.  Boot from Windows 7 install disk with Windows recovery options only shows Windows 8-1 as OS (not Windows 7).


Would like to recover both Windows 7 AND Windows 8-1 partitions -f possible.

Not being very technical how , do i go about doing this fixing the MBR.  Procedure with steps please.


Should I hit NEXT on Windows Recovery Options Panel showing only Windows 8-1 > Will this fix my MBR and recover my Windows 7 partition


Should I load and install drivers to get access to hard disk as the Windows Recovery options Panel suggest in case my OS is NOT listed (in my case only Windows 8-1 is shown).  In latter case how shoud i go about loading these drivers as I do not have a clue how to go about doing this.


Is it an option to Boot from an genuine Windows 8-1 install disk instead?  Would this bring up my Windows 7 OS partition so that i can mix MBR and recover from that?


Thank you very much in advance for your help.



Edited by hamluis, 15 July 2018 - 05:39 AM.
Moved from Crashes/BSODs to Disk Management - Hamluis.

BC AdBot (Login to Remove)


#2 hamluis



  • Moderator
  • 56,295 posts
  • Gender:Male
  • Location:Killeen, TX
  • Local time:02:55 AM

Posted 15 July 2018 - 05:38 AM

FWIW:  Probably of no value but...I triple-boot (XP, Win 7, Win 10) and my experience tells me that addressing the oldest/older O/S...is the wrong approach when facing boot problems on one or more of the O/Ses.


It seems that, when multibooting, each successful install of Windows version, supercedes the previous boot files.  In my case, the XP boot files are superceded by Win 7 when I dual-boot...and then those boot files are superceded by the Win 10 boot files when I install it.


If I have a XP boot problems after 1 or more installs of more recent versions of Windows...I need to address it from the functioning more recent install because using the XP install disk to attempt repair of boot problems...will just break the bool process...and I will wind up reinstalling the triple boot in the correct order (XP, Win 7, Win 10).




An alternative which MAY work...is to use EasyBCD, following the proper set of instructions.  I can't address using EasyBCD with Win 8.1 but I believe that I would install it in Win 8.1 (assuming that you can boot into it) and then try to correct the situation.



#3 FredinBB

  • Topic Starter

  • Members
  • 2 posts
  • Local time:09:55 AM

Posted 15 July 2018 - 07:11 AM

Thanks hamlouis for this interesting and usefull reply. 

So, the first message is start repair from the install DVD from most recent OS (8-1 in my case) - makes sense.

Alternatively I will also look into the EasyBCD tool.



Guess somewhere in the repair process that follows i should execute the FIXMBR comand

Only hope that after the MBR is fixed I can somewhow still rebuild/regain access to the other/older OS.



#4 JohnC_21


  • Members
  • 24,448 posts
  • Gender:Male
  • Local time:03:55 AM

Posted 15 July 2018 - 09:38 AM

If you can boot into one OS then EasyBCD is the best option.


If the computer came pre-installed with 8.1 or if pre-installed with Windows 7 and the computer has UEFI firmware then the hard drive will have a GPT partition table and no MBR. FIXMBR would not work. The Fixboot option is used. You can confirm if you are using a GPT disk by looking for a EFI partition formatted FAT32 in Disk Management. Repairing a MBR or EFI partition is tough on a dual boot system. 


If you want to recover the data on the partitions then either connect the drive to another computer using a USB adapter or use a live linux disk like Mint Cinnamon or use Hirens Boot DVD. You can copy data to a USB external drive. 

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users