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The other day, I decided to do a clean install of Fedora 27 on my Asus U24E laptop. I dual boot my laptop with Windows 10, so I figured I would just delete the partition containing my old Fedora install (while in Windows) and then boot up a live USB to install the new version of Fedora. Unfortunately, upon rebooting, I wasn't able to access the BIOS (which can usually be accessed by pressing F2 at the ASUS logo) and was instead greeted with the GRUB rescue prompt. This was a new experience for me, so I wasn't sure what to do. If the Linux system still exists on your hard drive, you can use commands like those found here to start things up and fix things, but I had deleted my Fedora install, so I was completely stuck. I ended up looking around for a couple of days trying to find a solution (e.g., [1], which did NOT work for me), but nothing seemed to be working. Not having access to the BIOS made me feel completely helpless. I eventually came across a suggestion (I can't remember where) that said removing your hard drive will allow you boot into the BIOS, and lo and behold, that worked. Once I regained access to the BIOS, I was able to start up the live USB and install Fedora without a hitch.
My success was short lived, however. I noticed after installing Fedora that I had some wasted space outside of both my Windows and Linux partitions, so I decided to shrink and move my Windows partition to make more room for my Fedora install. I used the AOMEI Partition Assistant to move/shrink the Windows volume, but, upon completion, Windows was no longer showing up in the GRUB menu. I wasn't too worried initially, as this had happened to me before, so I just ran:
sudo grub2-mkconfig -o /boot/grub2/grub.cfgto try to get GRUB to locate the Windows install. Not found... uh-oh. After some minor panic and looking around, I came across this page, which got me on the right track. My Windows system had apparently gone into "hibernate" mode, which made it visible to my Linux partition but inaccessible. By issuing the following command:
sudo mount -t ntfs-3g -o remove_hiberfile /dev/sda1 /media/windowsI was able to remove the hibernation file, which allowed grub2-mkconfig to find my Windows install.