[ubuntu] Ubuntu not booting after uninstalling Windows

Can anyone please help.

I am a newbie to Linux/Ubuntu and brought a new build laptop with 'no operating' system so that I could install Ubuntu Mate. When I first tued the laptop on it booted into a Windows 10 screen (although nothing there as I hadn't brought the software). The supplier explained they had put on Windows 10 to test the laptop.

I installed Ubuntu Mate 15.10 as a dual boot thinking it might be useful to keep Windows in case need to dual boot in the future (this was before I since found out about Virtual machines). I have been using the laptop for a couple of months but recently started to get messages that disk space ruing out. When I looked in Gparted it showed that a windows partition was taking up about 90GB of my 120GB hard drive with only about 10GB assigned to Ubuntu so I decided to uninstall Windows using OS-Uninstaller but got error message (please see attached screenshot).When I looked in Gparted all the windows partitions were still there and using the same amount of hard drive space so I assumed OS-Uninstaller had failed in the uninstall of Windows so I deleted the windows partitions in GP parted.

The laptop is now unable to boot into Ubuntu.

I have spent 3 days trying to fix the problem (including using Boot-Repair) and now understand (or think I understand) that I should not have deleted the windows EFI partition as that is where ubuntu was boot loading. I tried changing the boot manager from EFI to BIOS but ubuntu still not booting.

I had saved my working files but did not create a disk image backup so caot restore everything to what it was before. I do not want to reinstall ubuntu as I will lose all the software I installed (which took hours/days to install as I am new to Linux) and most importantly don't want to lose all my search engine history and bookmarks as urgently need it for my work.

Can anyone help me to get the Ubuntu on my hard drive to boot? Here is a link to the boot info http://paste.ubuntu.com/15959459/

If it helps:
sda is the hard drive
sdb is the ubuntu mate 15.10 live usb
sdc & sdd are usbs (data files – no operating systems on them)