Re: Destroyed filesystem
Cancelling out of the installation left the machine in some kind of interim state -- and in that case, it won't be able to finish booting from the hard drive.
The very least you need to find out is if you overwrote or otherwise damaged the Win7 install already on the drive.
To do that, you will have to boot from an Ubuntu LiveCD or LiveUSB. There's no way around that.
Your getting the GRUB messages means your BIOS is still trying to boot from the hard drive. You will have to go into the BIOS settings and change it to boot from the CD or USB -- whichever you need.
You typically change boot options on modern PCs by pressing F12.
Once you get to an Ubuntu desktop, open a terminal and enter "sudo fdisk -lu" (without the quotes and using a lowercase L, not a one). That will list out the partitions on the drive. Post the result back here.
Ubuntu 15.04 Mate, Mint 17.1; MS Win 8.1, Win10 TP.
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