Partition is completely invisible

[slmnceyhun]

After I installed Ubuntu 14 to my pc I messed up and lost the MBR of my Win7 installation, in Ubuntu I was able to see my drive and the files inside it (windows, program files etc...) I was looking for a solution and I found this page http://ubuntuhandbook.org/index.php/2013/08/repair-windows-mbr-from-ubuntu/, I did followed as the page was suggesting and suddenly my partition was lost, im fairly new to ubuntu so sorry if im explaning all this in a verry simple way.

When I type
sudo fdisk -l this is what I get;


Disk /dev/sda: 320.1 GB, 320072933376 bytes255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xd65287a5


Device Boot Start End Blocks Id System
/dev/sda1 257040 285282269 142512615 7 HPFS/NTFS/exFAT
/dev/sda2 * 285276160 314570751 14647296 83 Linux
/dev/sda3 314571600 625136399 155282400 7 HPFS/NTFS/exFAT


Disk /dev/sdb: 8283 MB, 8283750400 bytes
28 heads, 44 sectors/track, 13132 cylinders, total 16179200 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000552f4


Device Boot Start End Blocks Id System
/dev/sdb1 * 2048 16179199 8088576 b W95 FAT32

I installed
sudo apt-get update; sudo apt-get install syslinux
than used
sudo dd if=/usr/lib/syslinux/mbr.bin of=/dev/sda3 (sda3 instead of sda)
After that dint help I tryed with
sudo dd if=/usr/lib/syslinux/mbr.bin of=/dev/sda too but that didnt help either.

/dev/sda3 is the partition what I cant reach, not from ubuntu or with win7 recovery. sda1 and sda2 are visible and working correct.

I need to reach the data in sda3 please, if its possible. Thank you.

Edit: Oh and here is the Bootinfo link http://paste.ubuntu.com/9826710/

[oldfred]

You never install anything to a NTFS partition boot sector or PBR. That has essential Windows boot info in it.

You may be able to undo it, as it does have a backup PBR, if not you need a Windows repair flash drive to totally rebuild PBR using bootsect.exe.
You want to get to this screen:
http://www.cgsecurity.org/wiki/TestDisk_Step_By_Step#NTFS_Boot_sector_recovery
[HowTo] Repair the bootsector of a Windows partition - YannBuntu
https://help.ubuntu.com/community/BootSectorFix
http://ubuntuforums.org/showthread.php?t=1926510

[slmnceyhun]

Thank you, selecting [Advanced] instead of [Analyse] and selecting [BackupBS] made my partititon visible again, than i fixed my MBR and all was fixed.