It looks like your NTFS partition is corrupt.
You may also want to download http://www.cgsecurity.org/wiki/TestDisk which will allow looking for deleted partitions and make image backups of data, if necessary.
Here is an example of running gdisk. Please post your output.
The second command 'b' will create a backup file containing your GPT, before any changes are made. I would recommend copying the backup file to an external USB drive.
sudo gdisk /dev/disk0
Password:
GPT fdisk (gdisk) version 0.8.9
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): p
Disk /dev/disk0: 1954210120 sectors, 931.8 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 6ED0C429-00D1-4759-B50E-04B6FB80D0E3
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 1954210086
Partitions will be aligned on 8-sector boundaries
Total free space is 1293 sectors (646.5 KiB)
Number Start (sector) End (sector) Size Code Name
1 40 409639 200.0 MiB EF00 EFI System Partition
2 409640 1452940543 692.6 GiB AF00 Customer
3 1452940544 1454210079 619.9 MiB AB00 Recovery HD
4 1454211072 1954209791 238.4 GiB 0700 BOOTCAMP
Command (? for help): b
Enter backup filename to save: MyGPTBackup
The operation has completed successfully.
Command (? for help): q