Level 1

8 points

Windows XP BootCamp partition fails to boot after fixmbr command in XPs recovery console

First, I am having a Windows XP BootCamp partition on a mid 2009 MacBook Pro, running OS X 10.11.6.

I needed to fix booting sectors on my Windows XP BootCamp partition and decided to run the recovery console from the Windows XP Installation Disk. Previously I had read that it seemed safe to do so ( Re: Does fixmbr and/or fixboot damage bootcamp? ).

However, after running both fixmbr command followed by fixboot command in the recovery console, I ended up with a Bootcamp partition that won't boot anymore and instead displaying an error that NTLDR was missing. Furthermore, when trying to use recovery console again, the Windows root prompt disappeared and only the drive prompt was still there (C:\ instead of C:\Windows).

I decided to copy both NTLDR and NTDETECT from the Installation Disk onto the drive, but the Bootcamp partition would still not boot.

I am now hoping that there may be a way to rescue the partition via OS X.

I ran "sudo gpt -r -vv show disk0" and received:

gpt show: disk0: mediasize=500107862016; sectorsize=512; blocks=976773168

gpt show: disk0: Suspicious MBR at sector 0

gpt show: disk0: Pri GPT at sector 1

gpt show: disk0: Sec GPT at sector 976773167

start size index contents

0 1 MBR

1 1 Pri GPT header

2 32 Pri GPT table

34 6

40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

409640 900507832 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

900917472 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

902187008 66197504 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

968384512 8388623

976773135 32 Sec GPT table

976773167 1 Sec GPT header

Index 4 should be my Bootcamp partition, judging by the the content EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

Running "sudo fdisk /dev/disk0" resulted in:

Disk: /dev/disk0 geometry: 60801/255/63 [976773168 sectors]

Signature: 0xAA55

Starting Ending

#: id cyl hd sec - cyl hd sec [ start - size]

------------------------------------------------------------------------

1: EE 1023 254 63 - 1023 254 63 [ 1 - 409639] <Unknown ID>

2: AF 1023 254 63 - 1023 254 63 [ 409640 - 900507832] HFS+

3: AB 1023 254 63 - 1023 254 63 [ 900917472 - 1269536] Darwin Boot

*4: 0C 1023 254 63 - 1023 254 63 [ 902187008 - 66197504] Win95 FAT32L

However, in "diskutil list" Microsoft Data is recognized, not sure if the fact that it was Bootcamp partition is recognized

/dev/disk0 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *500.1 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_HFS Macintosh HD 461.1 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

4: Microsoft Basic Data ÿ÷ PSSìàÓ■ 33.9 GB disk0s4

Does anyone have an idea how I might be able to restore the function of my Bootcamp partition?

MacBook Pro, OS X El Capitan (10.11.6)

Posted on Dec 11, 2016 11:46 AM

28 replies

Loner T

Level 9

59,536 points

Dec 14, 2016 4:40 PM in response to TMBGJO

Please try (and enter your password when prompted). Each line is an individual command.

sudo mkdir -p /Volumes/TBCMP

sudo mount -t msdos /dev/disk0s4 /Volumes/TBCMP

ls -lgh /Volumes/TBCMP

TMBGJO Author

Level 1

8 points

Dec 15, 2016 3:16 AM in response to Loner T

Loner T wrote:

Please try (and enter your password when prompted). Each line is an individual command.

sudo mkdir -p /Volumes/TBCMP

sudo mount -t msdos /dev/disk0s4 /Volumes/TBCMP

I tried using the commands you posted, after the second command I am receiving an error

"mount_msdos: /dev/disk0s4 on /Volumes/TBCMP: Invalid argument"

Loner T

Level 9

59,536 points

Dec 15, 2016 5:09 AM in response to TMBGJO

Can you try

sudo mount -v -t msdos /dev/disk0s4 /Volumes/TBCMP

Here is my Terminal session mounting the EFI partition on my Mac.

sudo mkdir -p /Volumes/EFI

Password:

df -h

Filesystem Size Used Avail Capacity iused ifree %iused Mounted on

/dev/disk0s2 354Gi 223Gi 131Gi 63% 58429518 34405058 63% /

devfs 331Ki 331Ki 0Bi 100% 1148 0 100% /dev

map -hosts 0Bi 0Bi 0Bi 100% 0 0 100% /net

map auto_home 0Bi 0Bi 0Bi 100% 0 0 100% /home

/dev/disk0s4 122Gi 53Gi 69Gi 44% 173370 72757878 0% /Volumes/BOOTCAMP

sudo mount -t msdos /dev/disk0s1 /Volumes/EFI

df -h

Filesystem Size Used Avail Capacity iused ifree %iused Mounted on

/dev/disk0s2 354Gi 223Gi 131Gi 63% 58429563 34405013 63% /

devfs 331Ki 331Ki 0Bi 100% 1148 0 100% /dev

map -hosts 0Bi 0Bi 0Bi 100% 0 0 100% /net

map auto_home 0Bi 0Bi 0Bi 100% 0 0 100% /home

/dev/disk0s4 122Gi 53Gi 69Gi 44% 173370 72757878 0% /Volumes/BOOTCAMP

/dev/disk0s1 197Mi 73Mi 124Mi 37% 0 0 100% /Volumes/EFI

ls -lg /Volumes/EFI

total 108

-rwxrwxrwx 1 staff 54674 Oct 1 00:40 BOOTLOG

drwxrwxrwx 1 staff 512 Aug 7 19:30 EFI

TMBGJO Author

Level 1

8 points

Dec 15, 2016 5:51 AM in response to Loner T

Ok, here is my terminal session, "mount msdos" keeps returning "invalid argument"

sudo mkdir -p /Volumes/TBCMP

df -h

Filesystem Size Used Avail Capacity iused ifree %iused Mounted on

/dev/disk0s2 429Gi 345Gi 84Gi 81% 90589957 21973520 80% /

devfs 180Ki 180Ki 0Bi 100% 624 0 100% /dev

map -hosts 0Bi 0Bi 0Bi 100% 0 0 100% /net

map auto_home 0Bi 0Bi 0Bi 100% 0 0 100% /home

localhost:/9-U6NZyNg9ayO8cuA9OvMN 429Gi 429Gi 0Bi 100% 0 0 100% /Volumes/MobileBackups

sudo mount -v -t msdos /dev/disk0s4 /Volumes/TBCMP

mount_msdos: /dev/disk0s4 on /Volumes/TBCMP: Invalid argument

Loner T

Level 9

59,536 points

Dec 15, 2016 6:08 AM in response to TMBGJO

Are you familiar with Testdisk - http://www.cgsecurity.org/wiki/TestDisk_Download ?

TMBGJO Author

Level 1

8 points

Dec 15, 2016 6:48 AM in response to Loner T

No, I have not heard about it yet.

But I could give it a go

Loner T

Level 9

59,536 points

Dec 15, 2016 6:53 AM in response to TMBGJO

Let us try it. The worst-case scenario is that you will need to re-install WXP, and preserve the previous installation as Windows.old.

TMBGJO Author

Level 1

8 points

Dec 15, 2016 7:02 AM in response to Loner T

Ok, have just downloaded Testdisk

Loner T

Level 9

59,536 points

Dec 15, 2016 7:27 AM in response to TMBGJO

Can you use El Capitan has deleted my bootcamp windows partition as a reference and follow the Testdisk UI till you can see files in WXP partition?

TMBGJO Author

Level 1

8 points

Dec 15, 2016 8:04 AM in response to Loner T

Loner T wrote:

Can you use El Capitan has deleted my bootcamp windows partition as a reference and follow the Testdisk UI till you can see files in WXP partition?

Sorry if that is going slow now, I am not familiar with either gdisk nor test disk.

"sudo gdisk /dev/rdisk0" returned the following warning:

sudo gdisk /dev/rdisk0

GPT fdisk (gdisk) version 1.0.1

Warning: Devices opened with shared lock will not have their

partition table automatically reloaded!

NOTE: Write test failed with error number 1. It will be impossible to save

changes to this disk's partition table!

You may need to deactivate System Integrity Protection to use this program. See

https://www.quora.com/How-do-I-turn-off-the-rootless-in-OS-X-El-Capitan-10-11

for more information.

Partition table scan:

MBR: hybrid

BSD: not present

APM: not present

GPT: present

Found valid GPT with hybrid MBR; using GPT.

Do I need to deactivate System Integrity Protection?

Loner T

Level 9

59,536 points

Dec 15, 2016 8:24 AM in response to TMBGJO

Yes, you need to boot in Local Recovery and use csrutil disable to disable SIP temporarily.

TMBGJO Author

Level 1

8 points

Dec 16, 2016 3:22 AM in response to Loner T

Loner T wrote:

Can you use El Capitan has deleted my bootcamp windows partition as a reference and follow the Testdisk UI till you can see files in WXP partition?

I have followed the steps from your link, unfortunately, it did not recover my Bootcamp ( I must have really pulled a number on it). I think, I will just give up at this point and set everything up from scratch.

Thanks a million for your help Loner!

Loner T

Level 9

59,536 points

Dec 16, 2016 5:29 AM in response to TMBGJO

The only part of that discussion which was relevant was the Testdisk part.

If you are planning to re-install XP, please post back if you run into any issues.

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

Windows XP BootCamp partition fails to boot after fixmbr command in XPs recovery console