14.04 - Ubuntu and Windows 8.1 dual boot problem

I have Asus X550C laptop which came with FreeDOS on it.
I installed Windows 8.1 on it and then Ubuntu 14.04 LTS. Then when I rebooted the system only Ubuntu was booting up. I updated grub using sudo update-grub command and it found the Windows and everything was running smoothly.

But after a month I had to repair Ubuntu because of some issues. I booted with a boot-able USB and chose to repair the existing installation of Ubuntu. This time I can't locate Windows 8 for the life of me. I edited the grub file to show at start-up. Edited the grub file to add menu entry. But nothing.

Please help me boot windows as I have my life's work on that.

sudo parted -l

Model: ATA WDC WD5000LPVX-8 (scsi)

Disk /dev/sda: 500GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt

Number  Start   End    Size    File system     Name  Flags
 1      1049kB  538MB  537MB   fat32                 boot
 2      538MB   496GB  495GB   ext4
 3      496GB   500GB  4174MB  linux-swap(v1)