I bought a dell laptop with pre-existing ubuntu 14 installation. I use both ubuntu and windows on my main machine. when I tried to install windows alongside ubuntu 14 and after I formatted a space from the main drive for it, it told me it can't be installed on this disk because it's a gpt type disk, and the only solution is to delete the disk (in case of booting from usb, you can't boot to usb in uefi mode in this laptop). then I tried to enter ubuntu 14 again, but it wouldn't boot. with this message appearing: `error failure reading sector from 'hd1' so I searched for this message but all the solutions was about a live cd that won't boot. so after that I decided to follow this guide. I partitioned the disk as mentioned there but in uefi mode. then as mentioned I tried to format the windows partition in windows setup as a ntfs drive. the setup told me the same earlier message about gpt type disk. then I tried to open ubuntu 16 again and it booted into emergency mode.
I'm writing this post as I'm installing windows 10 after deleting the whole disk. this question is about knowing the exact reasons and for whom who might encounter the same problem to help him dodging this problem. and if there're some advices on installing ubuntu 16 next.
laptop is dell inspiron 5559 i5-6200U
I guess 20 years of GRUB aren't enough for Microsoft to just give up their crappy bootloader.. will take some 10 more years at least.
– Gewure Dec 12 '16 at 16:52