I got an HP Split x2 with Windows 8 pre-installed. I deleted it, and installed Ubuntu. However, I was wanting to play a few games that didn't work too well on wine, so I created a NTFS partition and installed Win 7 (UEFI) in it.
Windows was overwriting Grub all the time, and after a tiring struggle, I decided to get rid of Windows 7. I deleted its partition, but UEFI would still try to boot into it, which produced a black error screen ("0xc0000225 - The boot selection failed because a required device is inaccessible").
I googled a bit, and was told that Windows 7 installs a bootloader in the first partition. Well, I booted from a live CD, and deleted that partition via GParted. Oh, boy. Apparently, that was the EFI Boot partition, and now my laptop won't boot into anything other than live/install USB drives.
I tried boot-repair, and it told me to create an EFI partition, which I have no idea how to.
Is this fixable? Do I have to format my entire hard drive? The Ubuntu partition is still there (according to GParted), it is just not accessible. Thanks!