I'm a newbie (I'm a programmer but I'm just trying to work with Ubuntu!) and I've got a very seriuos situation...I explain myself:
I have an asus n550JV and it has EFI boot.....I decided to install Ubuntu next to windows 8 (I have a partition with Windows 8 and some other partitions that windows 8 needs to work fine + a rescue partition) so I followed the official guide....Since that everything fine....One day I decided to remove ubuntu and leave just Windows 8, so I went on windows and as I always do, I deleted the partition(and the related so also the swap) on Windows....Now when I enter in Bios there is yet a boot option called "ubuntu" that is referred to the hard disk and that doesn't work(I've deleted the partition so when I ty to use that there is as "usual error: no such partition. grub rescue>").....I tried everything to remove it(from bios I entered "remove option", from windows I used EasyBCD 2.2....); one more thing: I can't use anymore the USB live/CD live because the boot doesn't recognize them as before(when I first followed the guide I disabled the secure boot and then I could try Ubuntu with Uefi mode; right now I can use the USB live only if I enter in legacy mode, but obiuvsly all the kind of operation that involve Uefi aren't good because I started ubuntu in legacy mode ).....So now the question is how can I install again Ubuntu? I really need it! And above all, How can I let work the USB live? Thanks everybody and help me!