Q: Your PC/Device needs to be repaired

What is the year/model of your Mac? The solution you posted is not valid, unless we can confirm it is an issue with the MBR.

Resizing/repartitioning a Mac with Windows is not supported as documented in Boot Camp: Resize the Windows partition .

It may be possible to fix it. Please post the output of

diskutil list

diskutil cs list

sudo gpt -vv -r show /dev/disk0

sudo fdisk /dev/disk0

El Capitan requires that you disable SIP for modifying the MBR - About System Integrity Protection on your Mac - Apple Support .

Please post the output of

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

Step A. We need to disable SIP.

1. Boot into Local Recovery (Command+R).

2. Start Utilities -> Terminal.

3. Type csrutil disable in Terminal and press Enter/Return.

4. Type csrutil status.

5. Boot normally, and type csrutil status to confirm that all individual entries are still disabled.

Step B. Repeat your Fdisk steps. If you see any errors, stop and post back the errors/messages.

Did you reboot? Can you see Windows files in OS X Finder?

Your 2015 Mac does not support a MBR. Before we explore other methods, can Windows be removed and re-installed?

As a test, just remove the MBR using Gdisk. If you need commands, let me know. Once it is removed, check if you can still see the Bootcamp files in OS X Finder. If you can, we only need to correct your BCD.

You can remove the Hybrid MBR using the following sequence of Gdisk commands.

sudo gdisk /dev/disk0

x (Expert Menu)

o (print the current MBR)

n (create a protective MBR and remove Hybrid MBR)

o (print the current MBR)

p (print partition table)

w (Write)

y (Confirm Write)

Here is an example, without the last three commands.

sudo gdisk /dev/disk0

GPT fdisk (gdisk) version 1.0.0

 

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.

 

Command (? for help): x

 

Expert command (? for help): ?

a set attributes

c change partition GUID

d display the sector alignment value

e relocate backup data structures to the end of the disk

g change disk GUID

h recompute CHS values in protective/hybrid MBR

i show detailed information on a partition

l set the sector alignment value

m return to main menu

n create a new protective MBR

o print protective MBR data

p print the partition table

q quit without saving changes

r recovery and transformation options (experts only)

s resize partition table

t transpose two partition table entries

u replicate partition table on new device

v verify disk

w write table to disk and exit

z zap (destroy) GPT data structures and exit

? print this menu

 

Expert command (? for help): p

Disk /dev/disk0: 1000215216 sectors, 476.9 GiB

Logical sector size: 512 bytes

Disk identifier (GUID): 27F1F78B-B899-41D8-BA3C-37843C1662D8

Partition table holds up to 128 entries

First usable sector is 34, last usable sector is 1000215182

Partitions will be aligned on 8-sector boundaries

Total free space is 701 sectors (350.5 KiB)

 

Number  Start (sector)    End (sector)  Size       Code  Name

   1              40          409639   200.0 MiB   EF00  EFI System Partition

   2          409640       743086263   354.1 GiB   AF00  OSX-MBP13

   3       743086264       744355799   619.9 MiB   AB00  Recovery HD

   4       744355840      1000214527   122.0 GiB   0700  BOOTCAMP

 

Expert command (? for help): o

 

Disk size is 1000215216 sectors (476.9 GiB)

MBR disk identifier: 0x028A47A7

MBR partitions:

 

Number  Boot  Start Sector   End Sector   Status      Code

   1                     1       409639   primary     0xEE

   2                409640    743086263   primary     0xAF

   3             743086264    744355799   primary     0xAB

   4      *      744355840   1000214527   primary     0x07

 

We should test this, before you remove Windows and re-install it.