Fixing Destroyed MBR

[Michaelpeng]

What I really wanted to do: Since my OSX can't boot, I kept using Windows, but I want to reinstall OSX someday. Now I do. I decided to format the OS X partition to HFS+, and follow some online instructions which tells me to enter Internet Recovery. (I should actually select Recovery HD at startup directly, not via Internet Recovery)

What I did: pressing command+R at a normal startup. The MacBook Pro ran into Internet Recovery, which is a turning globe with completion bar under it. The recovery process took 3 mins. Then it goes into Recovery HD. The option is to install OSX Mountain Lion. I clicked into it, and it said it can't continue because I have a MBR instead of GPT. Then I tried to startup using Windows and look for more information. Unluckily, the only remaining thing in front of my eyes is a text of "Missing operating system".

What I tried to do to fix this problem: inserting the Windows 7 install DVD,trying to use chkdsk to see if there are any errors on the partition. CHKDSK reported the partition type is NTFS, no files damaged. Trying BOOTREC now. While /fixmbr worked successfully, /fixboot was unsuccessful. It said "The volume does not contain a recognized file system". The same message comes with /rebuildbcd.

See if there's anything to do in the utility in Recovery HD. Unfortunately, Disk Utility can't do anything with MBR.

Trying to obtain a Diskgenius, or PartitionGuru bootable CD. EFI does not recognize them.

Trying to obtain a WinPE bootable CD. EFI does not recognize it. Edit: UEFI does recognize it, but the computer is probably stuck at the Windows 8 logo.

I am asking for a way to let Windows come alive for this MacBook Pro. The files in Windows Partition is not damaged, only the unfixable MBR is damaged. (That is what I think Internet Recovery was doing, ruining my MBR!)

P.S.: The reason I put this in Hardware section is that MBR deals with hard drive, which is obviously, a hardware. P.P.S.: Happy New Year, buddies on the East Coast! It's already 2015 at your side! P.P.P.S.: This post is done on the Recovery HD.

 

[Joe C]

looks like you formatted your windows partition

 

[carnageX]

looks like you formatted your windows partition

It still recognizes there's a C:\Windows directory, so I don't think that's the case.

Try looking into the options on this page: How To Fix The Windows Bootloader » TweakHound

 

[Michaelpeng]

Status update: I am finally able to boot into Windows PE. Looking for further options with DISKPART. Anyway, thanks for the help!

Update: The method you provided didn't solve the problem. After the "nuclear" method, the volume still does not contain a recognized file system for fixboot and rebuildbcd commands, so they won't work. Anyways, I've got a copy of all the files on C:, so you can let me do whatever!

Ask: Can I transform the MBR to GPT? Since macs use EFI, and GPT is highly related to EFI.

Update: I found out a plan.
1. Go to Recovery HD and look for anything similar to Diskgenius that runs on mac. install it on the empty partition used to hold the mac system and change the type from MBR to GPT. Then install OS X and look for more options. Sounds good?

 

[Michaelpeng]

Sign of success: The recovery tools on the install disc is now able to detect Windows system as D:, Your suggestion might works.

Cheers!

 

[carnageX]

Yes, you can convert MBR to GPT:
http://www.disk-partition.com/gpt-mbr/convert-mbr-to-gpt-without-data-loss.html

 

[Michaelpeng]

Fatal Error: I found the Windows installation at the partition, but its driveletter is not what I expected. I selected the installation and opened the command prompt, then used diskpart to change the drive letter to C:. Without hesitation, I clicked on auto repair, (but the installation selected is still at the original drive letter so that it actually changes the boot record to the original drive letter, which is making the problem even worse) but it is probably stuck when attempting repair, while Cancel and X on top returned with a dialog "You cannot cancel this attempt" (OR PROBABLY SIMILAR). So, I did the worst thing: Force shutdown when the computer is still attempting to repair.

The next time I start my MacBook Pro, it was stuck in plain White screen, no keys worked. Neither Option, C, D, and more except Option+Command+P+R combination.

I did this, reset NVRAM. It is still stuck at white, and no keys worked as above.

I am planning to dispose this MacBook Pro with desperation. Any help is highly appreciated!

 

[Michaelpeng]

Fatal Error: I found the Windows installation at the partition, but its driveletter is not what I expected. I selected the installation and opened the command prompt, then used diskpart to change the drive letter to C:. Without hesitation, I clicked on auto repair, (but the installation selected is still at the original drive letter so that it actually changes the boot record to the original drive letter, which is making the problem even worse) but it is probably stuck when attempting repair, while Cancel and X on top returned with a dialog "You cannot cancel this attempt" (OR PROBABLY SIMILAR). So, I did the worst thing: Force shutdown when the computer is still attempting to repair.

The next time I start my MacBook Pro, it was stuck in plain White screen, no keys worked. Neither Option, C, D, and more except Option+Command+P+R combination.

I did this, reset NVRAM. It is still stuck at white, and no keys worked as above.

I am planning to dispose this MacBook Pro with desperation. Any help is highly appreciated!

I sent to Apple with this title:
EFI Firmware damage suspected (No keys work at startup, resetting NVRAM does not work)

In reply: I don't have Windows OS to use that tool. Let's get to it straight: My MacBook is now unable to do anything by itself, I have an external Windows laptop.

 

[Michaelpeng]

I had removed the hard drive. Let me know if connecting from the SATA to USB on another computer works.

 

[1etherer]

I had removed the hard drive. Let me know if connecting from the SATA to USB on another computer works.

Yes If you have a SATA to USB, you can hook it up to any laptop or PC. I had this problem before and managed to fix it but cant find my notes on how I done it.