Bootcamp fails after Yosemite upgrade (Plz help me Loner!)

I meant: after following the procedure above I did the test and Bootcamp did not show up on the list of startup disks. So I went into the second part of the procedure and entered:

sudo gdisk /dev/disk0

r <enter> go to the recovery & transformation menu

h <enter> create a new hybrid MBR

2 4 <enter> add partions 2 and 4 to the MBR

Place EFI GPT (0xEE) partition first in MBR (good for GRUB)? (Y/N): Y

Creating entry for GPT partition #2 (MBR partition #2)

Enter an MBR hex code (default AF): <enter>

Set the bootable flag? (Y/N): N

Creating entry for GPT partition #4 (MBR partition #3)

Enter an MBR hex code (default 07): <enter>

Set the bootable flag? (Y/N): Y

n <enter> do not protect more partitions

o < enter> print (display) the MBR

w <enter>

Can you post the output of

sudo gpt -vv -r show /dev/disk0

Did you reboot after changing the GPT? Please post the output of

sudo dd if=/dev/rdisk0s4 count=1 2>/dev/null | hexdump -C

Loner T, one more thing: before the whole mess-up with partitions, the EFI partition was not visible in Finder. Now it is.

Also, when I boot into Windows repair mode, open the DOS command prompt and do a directory listing ("dir"), the system gives me the contents of the EFI drive, which indicates that Windows considers the EFI partition to be its C: drive

Yes, I did reboot.

PS I have a recent backup of my OS X and also of my Windows partition (using Paragon's Boot Camp Backup software) so I have no problem applying some hard measures to my drive 🙂. I would even format my Windows partition now without bothering you, but I am afraid that formatting and restoring using Paragon's BCB will not help and once I format the Bootcamp drive, there will be no way back. So I may even make it worse.

The EFI partition may have a Microsoft directory, which contains the BCD and boot logs. You can check the logs for any specific errors.

No M$ directory on the EFI partition.

However there is a new thread in this mystery: I started up my system from a separate OS X installation that I keep on an external drive and that systems shows Bootcamp on the list of bootable devices in the System Preferences -> Startup Disk. I thought that my problem was solved, but unfortunately this was not the case - when I booted back again to my main OS X installation located on the internal hard drive, it did not show the Bootcamp drive in the Startup Disk. Of course Windows did not start either.

I tried various combinations of restarting my PC, such as. e.g. setting Bootcamp as the Target Startup Disk when working on the secondary installation and restarting without booting from main OS X installation in the meantime, but nothing worked. So I have a feeling there is a small glitch that prevents my system from properly identifying the actual Windows partition,

One more thing: when I perform the first part of the "gdisk procedure", I noticed that the values shown in step 2 and step 10 are identical, i.e. the whole procedure seems to be not changing anything. Should that be the case?

One more thing: could it be that the EFI partition that magically showed on the list of drives (before the whole partition problem I could not see it in Finder) is causing all the havoc? When I boot from the external drive, it does not have the EFI partition, so it properly identifies the Bootcamp partition.

I feel like deleting the EFI partition from the main drive using gdisk and seeing what's going to happen 👿.

PS_STI wrote:

No M$ directory on the EFI partition.

However there is a new thread in this mystery: I started up my system from a separate OS X installation that I keep on an external drive and that systems shows Bootcamp on the list of bootable devices in the System Preferences -> Startup Disk. I thought that my problem was solved, but unfortunately this was not the case - when I booted back again to my main OS X installation located on the internal hard drive, it did not show the Bootcamp drive in the Startup Disk. Of course Windows did not start either.

What version of OS X is on the external disk?

I tried various combinations of restarting my PC, such as. e.g. setting Bootcamp as the Target Startup Disk when working on the secondary installation and restarting without booting from main OS X installation in the meantime, but nothing worked. So I have a feeling there is a small glitch that prevents my system from properly identifying the actual Windows partition,

Your Windows needs Startup Repair based on this behavior.

One more thing: when I perform the first part of the "gdisk procedure", I noticed that the values shown in step 2 and step 10 are identical, i.e. the whole procedure seems to be not changing anything. Should that be the case?

After the initial modifications have been written, the next iteration will show the values as set. Unless you change the values for every iteration, they should be preserved.

PS_STI wrote:

One more thing: could it be that the EFI partition that magically showed on the list of drives (before the whole partition problem I could not see it in Finder) is causing all the havoc? When I boot from the external drive, it does not have the EFI partition, so it properly identifies the Bootcamp partition.

I feel like deleting the EFI partition from the main drive using gdisk and seeing what's going to happen 👿.

The EFI Partition is normally hidden. Various utilities or manual mounting is possible. There will also show up in Disk Utility debug menu. Connect your external disk and post the output of diskutil list.

New developments: normally a new install of the OS X fixes some minor problems with partitions. So I upgraded my main installation (the one on the internal SSD) to El Capitan. And - pooof! - Bootcamp disk is visible again as one of the startup disks in my main installation.

However, it does not show up when booting with the "option" key pressed. I though: "cool, I know how to deal with that, gdisk is the answer (the second part of the procedure)". The problem is gdisk does not work under El Capitan 😠. So I am 99.9% sure my Windows will work now, the only problem is I cannot test it, as I cannot run gdisk and mark the 4th partition of my drive bootable.

Did I remember to mention that in the meantime I upgraded to El Capitan also on the secondary installation on the external HD? I didn't? Well, I did upgrade to El Capitan so there is nowhere I can run gdisk from as I have El Captains olny 😠. I have a Disk Warrior bootable USB drive ("DW USB") with an older version of OS X, so can boot from there, but it has the Applications folder locked (password protected) by the DW manufacturer, so I cannot add gdisk there. I also have a Yosemite Time Machine backup disk...

[UPDATE] I am downloading Yosemite (available in my list of purchases in the App Store) and will try to install it on one of the USB drives. Then install gdisk there and try to fix the partitions on the main drive. We'll see how it goes...

PS_STI wrote:

The problem is gdisk does not work under El Capitan 😠. So I am 99.9% sure my Windows will work now, the only problem is I cannot test it, as I cannot run gdisk and mark the 4th partition of my drive bootable.

ELC has System Integrity Protection enabled by default. To disable it temporarily for diagnostics purposes.

a. Boot into Local Recovery. Power down your Mac, power it back up, and hold the Command+R.

b. Run Utilities -> Terminal

c. Type csrutil disable

d. Exit Terminal

e. Reboot normally.

Ok, did that.

The effect was completely opposite to what I was expecting: did not get Windows to boot and the Bootcamp partition disappeared again from the list of the Startup Disks in OS X.

The Windows Startup Recovery does not work, as it says the disk is "locked".

I think I cannot boot from my original Win7 installation disk, as in the meantime I upgraded to Windows 10, so now have a completely different system installed.

I had backed up my Bootcamp installation using Paragon's Bootcamp Backup software, but it fails to restore from that backup - it seems that the backup itself is ok, but for some reason during the restore procedure the system stops at the stage of trying to create a partition on the destination disk (I am trying to use various external disks).

I am getting closer and closer to giving up...