Restore windows without recovery partition

Hi,

I have Inspiron 7537. It came with Windows 8. I had upgraded that to Windows 8.1. After sometime, I required Linux, so I removed Windows 8 and installed Ubuntu.

While installing Ubuntu, I accidently allowed Ubuntu to remove all the partition and create a single partition.

Before installing Ubuntu, I did create the backup USB stick of my Windows 8 installation.

Now, I want to switch back to Windows 8, but whenever I try to restore windows via boot manager, it says "The required partition not found".

When I try any other installation disk (a Windows 8 disk from my friend", it says "The installation does not match with the serial key".

How can I restore my backed up windows copy without the recovery partition?