I can't dual boot Ubuntu and Windows 7!

I had Ubuntu 14.04 installed on my system (Toshiba Satellite Pro S500), with partitions as below (all on one HDD)

1. Extended partiton
   1.1 Ubuntu 14.04 OS, mounted at / (root dir) FS ext4 200GB (logical partition)
   1.2 Ubuntu User Data, mounted at /home FS ext4 48GB (logical partition)
   1.3 Unallocated Space (to be used for installing Windows 7) 50GB


2. Linux Swap, 2GB (primary partition)

I tried to install Windows 7 on the unallocated space, however it did not work. I tried deleting the unallocated space, however it deleted the OS partition as well as the unallocated space, therefore rendering my Ubuntu not bootable/gone. Windows did not install in the unallocated space at all, leaving me with not a lot. All I have is the windows 7 installer on a USB, GParted ISO on usb and my computer
Any tips?