So I recently got a brand new harddrive for my laptop sony vaio E series. The brand isn't same as the one given by Sony (They gave Toshiba and now I have WD). And I decided to install ubuntu instead of windows.
I followed the steps given in https://help.ubuntu.com/community/UEFI
but the system gives an error "OS not found" whenever I boot.
I also did boot repair following the instructions in https://help.ubuntu.com/community/Boot-Repair but with no luck.

Here's the link that I got from boot-repair - http://paste.ubuntu.com/7216824

I do not understand the problem at all. I'm just a rookie when it comes to ubuntu.

the change in manufacturer of hard-disk shouldn't be a factor because the same error was given by sony vaio E series when I tried to install windows 7 in a different laptop (with the same harddrive as it came with that laptop's manufacturer) using a usb stick. Also, in just 4$ service charges many sellers here install windows in new harddrives all the time.

Any help would be much appreciated.