As user Olfred pointed out, from your boot repair:
Drive: sda _____________________________________________________________________
Disk /dev/sda: 750.2 GB, 750156374016 bytes
255 heads, 63 sectors/track, 91201 cylinders, total 1465149168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
Partition Boot Start Sector End Sector # of Sectors Id System
/dev/sda1 1 1,465,149,167 1,465,149,167 ee GPT
GUID Partition Table detected.
Partition Start Sector End Sector # of Sectors System
/dev/sda1 2,048 999,423 997,376 EFI System partition
/dev/sda2 999,424 1,440,442,367 1,439,442,944 Data partition (Linux)
/dev/sda3 1,440,442,368 1,465,147,391 24,705,024 Swap partition (Linux)
You dedicated the majority of your sectors to the Data partition (linux). Total of 1.46 billion sectors, 1.43 bil sectors allocated to linux partition.
:(
Your windows install is gone, along with any data you had in it. Best you can do is reinstall windows. Installing Windows have the nasty tendency to break your grub. First make a live-usb of Ubuntu, install Windows, then head to this page:
https://help.ubuntu.com/community/RecoveringUbuntuAfterInstallingWindows
Just make sure you do a "side-by-side" install this time :)