Bootcamp problem, can't boot on windows anymore

Question

Level 1

8 points

Bootcamp problem, can't boot on windows anymore

Hi everyone.

To sum up my problem, I installed windows 7 ultimate a long time ago via bootcamp on my macbook air 2014. It worked perfectly but then i realized that the partition created for windows was too small.

So I tried to create a third partition using the disk utility of my mac os x. After i tried that, I rebooted my computer by pressing ALT so that i boot on windows, but the problem is that windows doesn't appear anymore in the list of disk i can boot my computer on. Not only that, but also when i try to reboot directly windows from my mac os x, it doesn't work neither, it says that there is "No bootable device, insert boot disk and press any key"

So now im stuck. Is there any way to make my windows device appear again?

Thank you very much for your help.

Posted on Mar 25, 2015 5:56 PM

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Answer 1

Loner T

Level 9

59,471 points

Mar 25, 2015 6:00 PM in response to Blablablox

Your MBR is now invalid. From OS X Terminal, can you post the text output of the following commands?

diskutil list

diskutil cs list

sudo gpt -vv -r show /dev/disk0

sudo fdisk /dev/disk0

Sudo commands require your password, which will not be echoed back. It may also warn you about improper use and potential data loss.

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Answer 2

Blablablox Author

Level 1

8 points

Mar 25, 2015 6:20 PM in response to Loner T

diskutil list

/dev/disk0

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *251.0 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_HFS Macintosh HD 125.1 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

4: Microsoft Basic Data BOOTCAMP 125.0 GB disk0s4

diskutil cs list

No CoreStorage logical volume groups found

sudo gpt -vv -r show /dev/disk0

gpt show: /dev/disk0: mediasize=251000193024; sectorsize=512; blocks=490234752

gpt show: /dev/disk0: Suspicious MBR at sector 0

gpt show: /dev/disk0: Pri GPT at sector 1

gpt show: /dev/disk0: Sec GPT at sector 490234751

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 244416696 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

244826336 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

246095872 244137984 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

490233856 863

490234719 32 Sec GPT table

490234751 1 Sec GPT header

sudo fdisk /dev/disk0

Disk: /dev/disk0 geometry: 30515/255/63 [490234752 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 - 244416696] HFS+

3: AB 1023 254 63 - 1023 254 63 [ 244826336 - 1269536] Darwin Boot

4: 0C 1023 254 63 - 1023 254 63 [ 246095872 - 244137984] Win95 FAT32L

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Answer 3

Loner T

Level 9

59,471 points

Mar 25, 2015 7:25 PM in response to Blablablox

Please post the output of

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

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Answer 4

Blablablox Author

Level 1

8 points

Mar 26, 2015 4:22 AM in response to Loner T

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 20 ab 0e |........?.... ..|

00000020 00 00 00 00 80 00 80 00 ff 3f 8d 0e 00 00 00 00 |.........?......|

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 d1 c1 cf 5a f3 cf 5a 62 |...........Z..Zb|

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 70 0e 16 68 09 00 66 53 66 53 66 |h...hp..h..fSfSf|

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

00000110 28 10 b9 d8 0f fc f3 aa e9 5f 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 a0 f8 01 e8 09 00 |...u...fa.......|

00000170 a0 fb 01 e8 03 00 f4 eb fd b4 01 8b f0 ac 3c 00 |..............<.|

00000180 74 09 b4 0e bb 07 00 cd 10 eb f2 c3 0d 0a 41 20 |t.............A |

00000190 64 69 73 6b 20 72 65 61 64 20 65 72 72 6f 72 20 |disk read error |

000001a0 6f 63 63 75 72 72 65 64 00 0d 0a 42 4f 4f 54 4d |occurred...BOOTM|

000001b0 47 52 20 69 73 20 6d 69 73 73 69 6e 67 00 0d 0a |GR is missing...|

000001c0 42 4f 4f 54 4d 47 52 20 69 73 20 63 6f 6d 70 72 |BOOTMGR is compr|

000001d0 65 73 73 65 64 00 0d 0a 50 72 65 73 73 20 43 74 |essed...Press Ct|

000001e0 72 6c 2b 41 6c 74 2b 44 65 6c 20 74 6f 20 72 65 |rl+Alt+Del to re|

000001f0 73 74 61 72 74 0d 0a 00 8c a9 be d6 00 00 55 aa |start.........U.|

00000200

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Answer 5

Loner T

Level 9

59,471 points

Mar 26, 2015 4:33 AM in response to Blablablox

Please execute the following steps and test. Ignore the i386 MBR error message when you execute the following commands. The following code make MBR#4 bootable and marks it as NTFS (0x07) rather than FAT (0x0C).

sudo fdisk -e /dev/disk0

p

setpid 4

07

flag 4

p

w

y

Reboot.

Test 1 - Can you see Bootcamp Volume in Finder?

Test 2 - Can you see files in the Bootcamp volume?

Test 3 - Can you select Bootcamp in System Preferences -> Startup Disk?

Test 4 - If Test 3 is successful, select Bootcamp and click on Restart.

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