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Anim

macrumors 6502a
Original poster
Dec 16, 2011
616
25
Macclesfield, UK
Woes!

Where has my Windows 8.1 partition gone! I was on a windows game last night, everything was running smoothly, no problems at all. Shutdown normally and went to bed.

Started my Mac Pro this morning by just powering it on (defaults to booting into OSX for work) and it was stuck in some kind of reboot loop saying there was a problem starting up. I held down alt key and booted into recover partition and looked at disk utility, it said there was a EFI boot error.

I tried a repair which said it couldn't repair it.

I then rebooted again holding ALT and just the Macintosh + Recovery partitions showed up as options.

I tried booting into OSX and it loaded fine this time, went into disk utility and the BOOTCAMP partition is there, I can view all the files on it too.

Any ideas how to repair the boot sector so I can get both OSX and Windows as options again?

(I am currently creating a disk image of bootcamp to an external)

New Mac Pro, 512GB SSD, Bootcamp and OSX on internal SSD. Windows is 8.1. I tried Parallels Desktop and deleted it when the trial ended about 2 weeks ago, I have added a secondary monitor last night via HDMI and thats it for the last couple of weeks. No other software installs. I scan for viruses almost daily using malware bytes software. I don't visit dodgy websites.

So, no idea how this occurred between this morning and last night. The only thing I did was disconnect everything the day before for an office rearrange.

I have not resized any partition since buying the mac.

Any help would be much appreciated.
 
Woes!

Where has my Windows 8.1 partition gone! I was on a windows game last night, everything was running smoothly, no problems at all. Shutdown normally and went to bed.

Started my Mac Pro this morning by just powering it on (defaults to booting into OSX for work) and it was stuck in some kind of reboot loop saying there was a problem starting up. I held down alt key and booted into recover partition and looked at disk utility, it said there was a EFI boot error.

I tried a repair which said it couldn't repair it.

I then rebooted again holding ALT and just the Macintosh + Recovery partitions showed up as options.

I tried booting into OSX and it loaded fine this time, went into disk utility and the BOOTCAMP partition is there, I can view all the files on it too.

Any ideas how to repair the boot sector so I can get both OSX and Windows as options again?

(I am currently creating a disk image of bootcamp to an external)

New Mac Pro, 512GB SSD, Bootcamp and OSX on internal SSD. Windows is 8.1. I tried Parallels Desktop and deleted it when the trial ended about 2 weeks ago, I have added a secondary monitor last night via HDMI and thats it for the last couple of weeks. No other software installs. I scan for viruses almost daily using malware bytes software. I don't visit dodgy websites.

So, no idea how this occurred between this morning and last night. The only thing I did was disconnect everything the day before for an office rearrange.

I have not resized any partition since buying the mac.

Any help would be much appreciated.

Try to boot the recovery partition and open disk utility then select your SSD -> click on repair disk

Edit : Sorry didnt read you did that part already

Try to first backup the bootcamp partition from disk utility while you can still see it before taking any attempt at repairing it.
Once its done do you have techtool pro 7?
 
Try to boot the recovery partition and open disk utility then select your SSD -> click on repair disk

Edit : Sorry didnt read you did that part already

Try to first backup the bootcamp partition from disk utility while you can still see it before taking any attempt at repairing it.
Once its done do you have techtool pro 7?

Hi

I don't have tectool Pro, no. Is TestDisk any good? http://www.cgsecurity.org/wiki/TestDisk

Thanks for helping.
 
Dont mess up your own drive! I will be back later, have to go on an errand while this backup is running. Cheers
 
Dont mess up your own drive! I will be back later, have to go on an errand while this backup is running. Cheers

Even if I mess it up I have an xServe running as a TimeMachine server at home for all my Mac Clients and my rMBP is backed up on it 15 minutes ago!
I just need to find out how that software is running and it will be my pleasure to help you with that!
 
Maybe an app did. I had this kind of problem until I encrypted both Operating systems.

First time I ever heard of that happening by mistake and I used to work on a project to encrypt the hard drives of 4500 laptops for the National Bank of Canada. Laptop don't just resize or delete partitions or volumes. Users doing it by mistake do. There is nothing magical that will make an app behave in such a matter, only users that might be working too much, striking a key by mistake, hit the mouse while it clicks or something like that...
 
First time I ever heard of that happening by mistake and I used to work on a project to encrypt the hard drives of 4500 laptops for the National Bank of Canada. Laptop don't just resize or delete partitions or volumes. Users doing it by mistake do. There is nothing magical that will make an app behave in such a matter, only users that might be working too much, striking a key by mistake, hit the mouse while it clicks or something like that...

I'm not so sure about that. While I never had the need to write an app to access the partition, I suspect you could. Just like I could write to the registry to store values.
 
I'm not so sure about that. While I never had the need to write an app to access the partition, I suspect you could. Just like I could write to the registry to store values.

Well on the Mac side any modifications to the system need to be authenticated with the users password ;)
Which only leave windows... the enemy to shoot down... that OS is quite problematic but AFAIK on 4500 laptops encrypted for bankers, only .4% came back for partition problems.
 
Woes!

Where has my Windows 8.1 partition gone! I was on a windows game last night, everything was running smoothly, no problems at all. Shutdown normally and went to bed.

Started my Mac Pro this morning by just powering it on (defaults to booting into OSX for work) and it was stuck in some kind of reboot loop saying there was a problem starting up. I held down alt key and booted into recover partition and looked at disk utility, it said there was a EFI boot error.

I tried a repair which said it couldn't repair it.

I then rebooted again holding ALT and just the Macintosh + Recovery partitions showed up as options.

I tried booting into OSX and it loaded fine this time, went into disk utility and the BOOTCAMP partition is there, I can view all the files on it too.

Any ideas how to repair the boot sector so I can get both OSX and Windows as options again?

(I am currently creating a disk image of bootcamp to an external)

New Mac Pro, 512GB SSD, Bootcamp and OSX on internal SSD. Windows is 8.1. I tried Parallels Desktop and deleted it when the trial ended about 2 weeks ago, I have added a secondary monitor last night via HDMI and thats it for the last couple of weeks. No other software installs. I scan for viruses almost daily using malware bytes software. I don't visit dodgy websites.

So, no idea how this occurred between this morning and last night. The only thing I did was disconnect everything the day before for an office rearrange.

I have not resized any partition since buying the mac.

Any help would be much appreciated.

On a real PC, it is possible to repair the boot sector (google search to have a look). Unfortunatly, I don't think it is possible on a bootcamp partition since it is located on the EFI partition (200MB) or on the windows reserved partition created during Windows installation. So, I think you have to start again from scratch, i.e remove your bootcamp partition with bootcamp assistant (hoping it works), then create a new bootcamp partition on your disk and install again windows. For safety, you can later create an image of your bootcamp partition with Winclone or create both an image of your bootcamp partition and of the EFI partition with Acronis true image. Not very good news, but hope it will be of some help.
 
Any luck EvilMonk?

There isn't a lot of options I can see in that tool.
You would be better to boot into recovery mode if you can. Boot on the Windows 8.1 install disk, I think you can repair the installation from there (Not format, there is a recovery option) when you start Windows installation.

There is a good guide here http://windowssecrets.com/forums/sh...air-Windows-8-(8-1)-Without-Losing-Everything

or if you can't even get in windows, boot off the install DVD and use this one!!! You have an option to keep all your files and reinstall Windows.
http://www.softwareok.com/?seite=faq-Windows-8&faq=26

Beside that, I don't see a lot of options... I would try this one maybe http://www.eightforums.com/tutorials/26095-repair-install-windows-8-a.html

but a good option might be to download hirens boot CD which has a lot of tools for partition repair on it.
Its free and it gives you a bootable from CD windows environment that is loaded in your RAM.
http://www.hirensbootcd.org/download/

Let me know how it goes!!
 
Well on the Mac side any modifications to the system need to be authenticated with the users password ;)
Which only leave windows... the enemy to shoot down... that OS is quite problematic but AFAIK on 4500 laptops encrypted for bankers, only .4% came back for partition problems.

I wrote bill payment software for the US banks about 10yrs ago. Correct me if I'm wrong, but once a drive is encrypted, it can no longer be resized.

With that in mind, you can recreate the OP's issue by encrypting the Win 8.1 first. Win 8.1 will resize the partition during the encryption process and the OS X partition will be gone. It's a bug in bootcamp if you ask me.
 
I wrote bill payment software for the US banks about 10yrs ago. Correct me if I'm wrong, but once a drive is encrypted, it can no longer be resized.

With that in mind, you can recreate the OP's issue by encrypting the Win 8.1 first. Win 8.1 will resize the partition during the encryption process and the OS X partition will be gone. It's a bug in bootcamp if you ask me.

I said came back for partition problems, not partition resize... I am talking about laptops that were halted while a crucial part of the encryption was taking place or drives that didn't survive the stress of the encryption...
 
Thanks guys.

Reinstalling windows is something I was hoping to avoid but if it's the solution then so be it. I will try to find out what happened in the first place too as I would rather this wasn't a recurring issue with my setup.

Thanks
 
Thanks guys.

Reinstalling windows is something I was hoping to avoid but if it's the solution then so be it. I will try to find out what happened in the first place too as I would rather this wasn't a recurring issue with my setup.

Thanks

You might have some success with hirens boot cd, I've put the link in my previous post :)
 
I am about to go through your links now. Fingers crossed :)

Used it quite a lot of times, its a tweakers magical cd, I was able to repair partitions with it, remove viruses and spywares from computers that I believed to be lost for good. theres so many good tools on there.
 
There isn't a lot of options I can see in that tool.
You would be better to boot into recovery mode if you can. Boot on the Windows 8.1 install disk, I think you can repair the installation from there (Not format, there is a recovery option) when you start Windows installation.

There is a good guide here http://windowssecrets.com/forums/sh...air-Windows-8-(8-1)-Without-Losing-Everything

or if you can't even get in windows, boot off the install DVD and use this one!!! You have an option to keep all your files and reinstall Windows.
http://www.softwareok.com/?seite=faq-Windows-8&faq=26

Beside that, I don't see a lot of options... I would try this one maybe http://www.eightforums.com/tutorials/26095-repair-install-windows-8-a.html

but a good option might be to download hirens boot CD which has a lot of tools for partition repair on it.
Its free and it gives you a bootable from CD windows environment that is loaded in your RAM.
http://www.hirensbootcd.org/download/

Let me know how it goes!!

The first link wasn't applicable as can't load windows to begin that fix

The second link showed different screens to my Win 8.1 install and different options too although there was an Advanced page where you can ask windows to look at issues stopping windows from booting, I ran this and after about 30 seconds it reported it couldn't fix the issue (and didn't make it worse).

I had a look at Hirenboot cd website ( http://www.hiren.info/pages/bootcd ) but there was nothing to help fix EFI boot partitions mentioned in the above link.

Looks like I'm going to have to go through Bootcamp, erase the old bootcamp partition, reinstall windows then try to restore the BOOTCAMP backup image I created earlier with disk utility. I will report how that goes.

Thanks
Anim
 
The first link wasn't applicable as can't load windows to begin that fix

The second link showed different screens to my Win 8.1 install and different options too although there was an Advanced page where you can ask windows to look at issues stopping windows from booting, I ran this and after about 30 seconds it reported it couldn't fix the issue (and didn't make it worse).

I had a look at Hirenboot cd website ( http://www.hiren.info/pages/bootcd ) but there was nothing to help fix EFI boot partitions mentioned in the above link.

Looks like I'm going to have to go through Bootcamp, erase the old bootcamp partition, reinstall windows then try to restore the BOOTCAMP backup image I created earlier with disk utility. I will report how that goes.

Thanks
Anim

There are a lot of partioning tools on the hirens boot cd. And a lot of other tools as well
 
I had the exact same problem with my nMP and Win 8.1 Bootcamp partition. Nothing seemed to work, until I tried migrating the partition over to an external drive via WinClone (Crucial m500 SSD via Thunderbolt) and haven't had any issues since. Added bonus of freeing up all the space on the onboard SSD!
 
^ this. I installed Windows on an external Thunderbolt partially to avoid such issues. Easier to fix when one OS goes down if you don't have to have to tiptoe around worrying about nuking the other OS in the process.
 
Saving an occasional image of your Windows environment with WinClone is also a good backup in the event your Windows installation gets corrupted and you have to start over again. Installing Window is such a pain with all the countless updates and reboots .... restoring your WinClone image is quick and painless, and it is all done under OS X.
 
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