Windows Boot Camp Partition replaced by System Reserved after installation

For those having similar problems as me.

I still do not know why the System Reserved partition did "overwrite" the Bootcamp partition.

In the end it did not matter. Just format the partition again and install windows again. During the next installations windows wouldn't create a System Reserved partition anymore.

If you are having problems getting Windows Bootcamp running without a USB-Stick I would highly recommend using this guide: Installing Windows 7 or 10 Pro 64 bit without DVD or Flash Drive.

The guide appears more complicated than it actually is and is very well written.

For those who don't understand all the code, dont worry, you basically just have to copy & paste everything.

Good Luck

@Loner T

I just found a 3 year old discussion you solved. Seems like this guy had the same problem as me.

Still, I do not have the required knowledge to do any further steps without screwing things up.

If you could guide me through the process, I would highly appreciate it!

Would even Paypal donate you a cup of coffee if thats allowed here 😁

Alright one last try of figuring this out myself.

I found these instructions on stackexchange.

I think thats it, right?

Rebuild MBR to match the new GPT information thus resetting the

Hybrid MBR. Use defaults for other questions (like partition codes). The

only values that need modifications are the Boot flags and step 10.

Accept all other defaults that Gdisk offers. These steps can be repeated

if you make a mistake before you get to Step 12, otherwise start from

Step 1 for these steps. Step 6 has numbers which are typed with a space

between the numbers.

1. sudo gdisk /dev/rdisk0
2. P (Print list of parts)
3. R (Recover)
4. O (print current Hybrid MBR)
5. H (chooses Hybrid)
6. Partitions numbers to be hybridized: 2 3 4
7. Y (Good for GRUB question)
8. N (part 2 boot flag), N (part 3 boot flag)
9. Y (part 4 boot flag make NTFS bootable partition)
10. O (print current Hybrid MBR)
11. W (Write the new MBR)
12. Y (Yes! write the new MBR)
13. Reboot

To make Windows bootable again try the following:

Boot from your Windows DVD/USB-Stick

Open command prompt from Windows recovery option menu. Type “diskpart” at the command prompt.

At the DiskPart prompt, type in “list disk”. You will see the list of disk currently attached to your computer.

Now type in “select disk n”, where n is the disk number. In this example, disk 0 is selected.

Now that correct disk is selected, type in “list partition” to get a list of all the partitions on that disk.

To select the partition you want to set as active, type in “select partition n”, where n is the partition number (probably 3).

Now that you have selected the disk and partition, mark it as

active by just typing the word “active” and pressing Enter. Now the

partition is set active.

Exit from the command prompt and run startup repair.

Except, I assume in my case I have to set bootflag on partition 3.

So step 6. looks like this: Partitions numbers to be hybridized: 2 3

And at step 8. I press N only once

And I dont understand what step 7. "Y (Good for GRUB question)" is meaning/doing, I guess its setting bootflag for the EFI so I can boot into MacOS?

So in summary and after reading the gdisk documentation about how to create hybrid MBR, I am coming to the conclusion that the steps I have to do are:

1. sudo gdisk /dev/rdisk0
2. C (change partitions name)
3. Partition number (1-3): 3
4. Enter name: Windows
5. R (recovery options)
6. H (make hybrid MBR)
7. Type from one to three GPT partition numbers, separated by spaces, to be added to the hybrid MBR, in sequence: 2 3
8. Place EFI GPT (0xEE) partition first in MBR (good for GRUB)? (Y/N): Y
9. Creating entry for partition #2. Enter an MBR hex code: af
10. Set the bootable flag? (Y/N): n
11. Creating entry for partition #3. Enter an MBR hex code: 07
12. Set the bootable flag? (Y/N): y
13. In case of: Unused partition space(s) found. Use one to protect more partitions? (Y/N): n
14. O (checking status of hybrid MBR)
15. Compare the start and end values to the start and end values for the GPT partitions, you should see that they match for the hybridized partitions.
16. W (write changes)

Can you confirm this? Is that all I have to do or am I missing something?

Ok I followed all those steps and rebooted.

Now, fdisk output is:

Disk: /dev/disk0	geometry: 60801/255/63 [976773168 sectors]
Signature: 0xAA55
         Starting       Ending
 #: id  cyl  hd sec -  cyl  hd sec [     start -       size]
------------------------------------------------------------------------
 1: EE    0   0   2 -   25 127  14 [         1 -     409639] <Unknown ID>
 2: AF   25 127  15 - 1023 254  63 [    409640 -  857421888] HFS+        
*3: 07 1023 254  63 - 1023 254  63 [ 857833472 -  118939648] HPFS/QNX/AUX
 4: 00    0   0   0 -    0   0   0 [         0 -          0] unused   

But still no bootcamp/system reserved option upon startup holding alt key.

What I did next is I used virtualbox and reinstalled windows. During the process I formatted the disk0s3 again with windows installer and chose that partition to install windows on. To my surprise this time windows did not create a system reserved partition. However I was able to boot into windows with virtualbox and changed the partition name to Bootcamp via properties like you said.

But still no bootcamp/system reserved option upon startup holding alt key.

So I did further research. I found out that Paragon NTFS could be preventing the partition to be bootable.

I followed the instructions to let MacOS remount the partition with its drivers:

1. Disable NTFS for Mac
2. Unmount and Remount with Macs diskutility.

But still the partition does not show up in System Preferences > Startup Disk.

And still not bootable.

I then used virtualbox to load the windows installer and used the repair tools, it said it detected some problems with the boot information and it automatically fixed it for me.

Still no success though.

Will do further research and report back.

One thing to note is, as soon as I restart my macbook, I cant use virtualbox anymore to boot windows.

I have to create a new .vmdk file for virtualbox and if I start guest I get a black screen like this:

I still think the problem comes from Paragon NTFS though. I might try reinstalling windows while having Paragon set to not automatically mounting the bootcamp drive.

Loner T, if you have any further advice I would really appreciate it 😄

Ok so I have made some progress.

First of all, I figured out that in order to get rid of all virtualbox errors I had to execute the chown commands again and also unmount the partition, each time after I reboot my Macbook.

sudo chown $USER /dev/disk0s3
sudo chown $USER /dev/disk0s1
sudo chown $USER /dev/disk0
diskutil unmount /dev/disk0s3

There was no need to create a new .vmdk at all.

Then I tried to reinstall windows and rebuild the hybrid MBR again with gdisk.

It seemed like nothing worked until I checked the Startup Disk in my MacOS Settings.

NOW I see it!

I figured out that I had to mount it in order to show up in Startup Disks.

Anyway, I still cant chose it from the startup screen. When I hold alt/option I only see my Mac OS SSD.

My new problem is:

When I use Startup Disk to Restart into "Untitled Windows" after 10 sec of grey screen I get stuck at a black screen with blinking cursor. (I waited more than 10 min)

I tried windows repair command prompt:

Bootrec.exe /FixMBR
Bootrec.exe /FixBoot
Bootrec.exe /RebuildBcd

But nothing changed...

Oh not sure if this helps but the virtualbox error message is:

Could not open the medium '/Users/%USER/RawWinDisk.vmdk'.

VD: error VERR_ACCESS_DENIED opening image file '/Users/%USER/RawWinDisk.vmdk' (VERR_ACCESS_DENIED).

Result Code:

NS_ERROR_FAILURE (0x80004005)

Component:

MediumWrap

Interface:

IMedium {4afe423b-43e0-e9d0-82e8-ceb307940dda}

Let me know if any other information is needed!

[Personal Information Edited by Host]

After some research around the web, I think these Terminal outputs might be of use:

sudo gpt -r -vv show disk0
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  857421888      2  GPT part - 7C3457EF-0000-11AA-AA11-00306543ECAC
  857831528       1944         
  857833472  118939648      3  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7
  976773120         15         
  976773135         32         Sec GPT table
  976773167          1         Sec GPT header

sudo fdisk /dev/disk0
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: FF 1023 254  63 - 1023 254  63 [    409640 -  857421888] Xenix BBT   
 3: 0B 1023 254  63 - 1023 254  63 [ 857833472 -  118939648] Win95 FAT-32
 4: 00    0   0   0 -    0   0   0 [         0 -          0] unused      

I also installed gdisk.

MYMACBOOK:~ MYNAME$ sudo gdisk -l /dev/disk0
GPT fdisk (gdisk) version 1.0.4

Warning: Devices opened with shared lock will not have their
partition table automatically reloaded!
Partition table scan:
  MBR: hybrid
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with hybrid MBR; using GPT.
Disk /dev/disk0: 976773168 sectors, 465.8 GiB
Sector size (logical): 512 bytes
Disk identifier (GUID): 6DEBDAF3-548A-4F2D-AE58-D4FBDE562F80
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 976773134
Partitions will be aligned on 8-sector boundaries
Total free space is 1965 sectors (982.5 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1              40          409639   200.0 MiB   EF00  EFI System Partition
   2          409640       857831527   408.9 GiB   AF0A  Mac OS X SSD
   3       857833472       976773119   56.7 GiB    0700  

I am really trying to learn a bit about partition tables MBR and GPT but I think I need a little help to understand why my Bootcamp partition disappeared and how to recover it.

I think I understand that Mac OS uses GPT but also creates an MBR at Sector 0, and its normal that sudo gpt says its suspicious because Bootcamp Assistant changes its status to hybrid for the Bootcamp Partition.

Now what I am wondering is:

Why does fdisk show ID#2 as Xenix BBT?

I found someone online stating that "Xenix was a Microsoft UNIX operating system in the 1980s".

Why does fdisk show ID#3 as Win95 FAT-32?

I assume that this partition should have been reformatted to NTFS during the windows installation, right?

I think the System Reserved partition from windows was originally created as FAT-32 as ID#4.

And then some kind of mixup with ID#3 and ID#4 happened? In case they changed position (I do not know the right terms here) I have no clue why ID#3 now shows a large size and ID#4 shows a size of 0 and "unused".

Can someone help me understand what happened?

Thank you so much for your answer Loner T.

Let me take some time to try to understand how to rebuild the MBR and come back with (hopefully not too many) questions.

By the way, do you have any clue what could have caused this?

Ok so I have been going through the gdisk documentation.

Changing the partition name seems easy to me:

sudo gdisk /dev/rdisk0 and then press c to change partition name and change it to "Windows" for example?

After that, I can press x in gdisk to get to extra functionality. From there I can press c to change the partition GUID to 07 and change the EFI GUID to EE? Is that correct? Should I change it to EE or EF, since gdisk already shows it to be EF?

I am a bit confused why gdisk already shows those ID's to be 07 and EF.

Gdisk works on the GPT table instead of MBR right? And what we need to fix is the MBR table? Thats doesn't really make sense to me. Wouldnt we need to do this with fdisk?

"We can rebuild the MBR from GPT using GDisk."

I am having a hard time to get a grasp of what that actually means. I glanced over the MBR wiki and I realize I have no idea what MBR and GPT really are.

What exactly is wrong with the MBR ?

Sorry if my curiosity makes this more complicated then it is. Maybe at this point its easier if you could just give me a rundown of how to use gdisk to accomplish this. And maybe I automatically get a better understanding of everything afterwards.