Repairing Boot Camp after creating new partition

On a single-disk system EFI, Recovery HD, OS X, Bootcamp form the 4 MBR entries.

Adding another HFS+ and Recovery HD will break stuff.

Running the dd command can tell if the NTFS side is intact. Windows Recovery may still be required.

If the Bootcamp volume mounts in the OS X Finder and you can see your files, then a.) the GPT partition entry for it is correct, b.) chances are the filesystem is OK. But that it doesn't boot suggests there's a bootloader problem, and to fix that is going to require using Window Startup Repair or bootrec.exe.

So there's no way to know if the NTFS is intact before I delete the new OS? (I tried to run the command sudo dd if=/dev/disk0s6 count=1 2>/dev/null | hexdump -C now, but nothing happens...)

Also, did you see my 2nd Q? (Another question, how come I can actually boot to the windows side (after using your trick..) it just gets stuck at the black loading screen)

Thanks again🙂

Oh, just came across your response.

Thanks for the so valuable info🙂

By saying that "there's a bootloader problem, and to fix that is going to require using Window Startup Repair" you mean that i don't need to delete the new created partition?

Oh, just came across your response.

Thanks for the so valuable info🙂

By saying that "there's a bootloader problem, and to fix that is going to require using Window Startup Repair" you mean that i don't need to delete the new created partition?

Use rdisk0s6.

Your boot loader is corrupted and requires startup repair.

(I tried to run the command sudo dd if=/dev/disk0s6 count=1 2>/dev/null | hexdump -C now, but nothing happens...)

That's because you made changes to the partition map, and you no longer have a disk0s6 (s6 means slice 6, a.k.a. partition 6). Now it's s4.

By saying that "there's a bootloader problem, and to fix that is going to require using Window Startup Repair" you mean that i don't need to delete the new created partition?

I don't know what you mean by "new created partition" I only see four partitions, and see no reason to delete any. So it looks like the Yosemite installer permits installing a 2nd instance of OS X onto a disk with an older version of OS X *and* Windows, and in so doing obliterates the hybrid MBR making Windows unbootable. I assume the final release of the installer disallows 2nd OS X instances, and instead only upgrades an existing one? Otherwise, this is yet another Bootcamp disaster in the making.

rdisk0s6

-bash: rdisk0s6: command not found

OK I'm wrong, I saw fbaux's response with 4 partitions and though it was AbrahamS_NY's. Yes, AbrahamS__NY you should try rdisk0s6 and see what happens.

I really should stick to my mantra of making thread jackers start their own thread, to avoid exactly this kind of confusion, so that everyone gets their own thread and no interruptions.

OK you're realllly not adapting at all, which means you don't at all understand what you're typing.

Instead of this

sudo dd if=/dev/disk0s6 count=1 2>/dev/null | hexdump -C

Use this

sudo dd if=/dev/rdisk0s6 count=1 2>/dev/null | hexdump -C

Oh thanks... Here's the results, and yes, I have no idea (as of now...) what I'm typing here...

00000000 eb 52 90 4e 54 46 53 20 20 20 20 00 02 08 00 00 |.R.NTFS .....|

00000010 00 00 00 00 00 f8 00 00 3f 00 ff 00 00 00 44 08 |........?.....D.|

00000020 00 00 00 00 80 00 80 00 ff 6f e9 14 00 00 00 00 |.........o......|

00000030 00 00 0c 00 00 00 00 00 02 00 00 00 00 00 00 00 |................|

00000040 f6 00 00 00 01 00 00 00 aa 58 cd 4e 95 cd 4e ac |.........X.N..N.|

00000050 00 00 00 00 fa 33 c0 8e d0 bc 00 7c fb 68 c0 07 |.....3.....|.h..|

00000060 1f 1e 68 66 00 cb 88 16 0e 00 66 81 3e 03 00 4e |..hf......f.>..N|

00000070 54 46 53 75 15 b4 41 bb aa 55 cd 13 72 0c 81 fb |TFSu..A..U..r...|

00000080 55 aa 75 06 f7 c1 01 00 75 03 e9 dd 00 1e 83 ec |U.u.....u.......|

00000090 18 68 1a 00 b4 48 8a 16 0e 00 8b f4 16 1f cd 13 |.h...H..........|

000000a0 9f 83 c4 18 9e 58 1f 72 e1 3b 06 0b 00 75 db a3 |.....X.r.;...u..|

000000b0 0f 00 c1 2e 0f 00 04 1e 5a 33 db b9 00 20 2b c8 |........Z3... +.|

000000c0 66 ff 06 11 00 03 16 0f 00 8e c2 ff 06 16 00 e8 |f...............|

000000d0 4b 00 2b c8 77 ef b8 00 bb cd 1a 66 23 c0 75 2d |K.+.w......f#.u-|

000000e0 66 81 fb 54 43 50 41 75 24 81 f9 02 01 72 1e 16 |f..TCPAu$....r..|

000000f0 68 07 bb 16 68 52 11 16 68 09 00 66 53 66 53 66 |h...hR..h..fSfSf|

00000100 55 16 16 16 68 b8 01 66 61 0e 07 cd 1a 33 c0 bf |U...h..fa....3..|

00000110 0a 13 b9 f6 0c fc f3 aa e9 fe 01 90 90 66 60 1e |.............f`.|

00000120 06 66 a1 11 00 66 03 06 1c 00 1e 66 68 00 00 00 |.f...f.....fh...|

00000130 00 66 50 06 53 68 01 00 68 10 00 b4 42 8a 16 0e |.fP.Sh..h...B...|

00000140 00 16 1f 8b f4 cd 13 66 59 5b 5a 66 59 66 59 1f |.......fY[ZfYfY.|

00000150 0f 82 16 00 66 ff 06 11 00 03 16 0f 00 8e c2 ff |....f...........|

00000160 0e 16 00 75 bc 07 1f 66 61 c3 a1 f6 01 e8 09 00 |...u...fa.......|

00000170 a1 fa 01 e8 03 00 f4 eb fd 8b f0 ac 3c 00 74 09 |............<.t.|

00000180 b4 0e bb 07 00 cd 10 eb f2 c3 0d 0a 41 20 64 69 |............A di|

00000190 73 6b 20 72 65 61 64 20 65 72 72 6f 72 20 6f 63 |sk read error oc|

000001a0 63 75 72 72 65 64 00 0d 0a 42 4f 4f 54 4d 47 52 |curred...BOOTMGR|

000001b0 20 69 73 20 63 6f 6d 70 72 65 73 73 65 64 00 0d | is compressed..|

000001c0 0a 50 72 65 73 73 20 43 74 72 6c 2b 41 6c 74 2b |.Press Ctrl+Alt+|

000001d0 44 65 6c 20 74 6f 20 72 65 73 74 61 72 74 0d 0a |Del to restart..|

000001e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|

000001f0 00 00 00 00 00 00 8a 01 a7 01 bf 01 00 00 55 aa |..............U.|

00000200

Looks like the boot sector is present. I can't tell if it's correct, but Windows Startup Repair hopefully can fix it. If not, then bootrec.exe and this document:

http://support.microsoft.com/kb/927392

Christopher Murphy wrote:

I really should stick to my mantra of making thread jackers start their own thread, to avoid exactly this kind of confusion, so that everyone gets their own thread and no interruptions.

Apologies, Christopher. I mention it every time I see a new request, but some do, some do not. I will try and suggest it a bit more forcefully next time.

Ok thanks!

Now lastly; Do I need to first delete Yosemite Partition? Agree with Loner T on that one?

Let me state my objection to the new OS on the same machine. It is non-standard with two Recovery HDs. On a clean mac, the volume has become CoreStorage rather than a regular HFS+. A new hybrid MBR may work, but on Beta software, it may fall apart due to bugs. Your Mavericks (or other OS) can create problems during software updates for itself or other side. You may lose data.