Sometimes Windows update destroys grub! When you boot you will get the grub commandline interface

Boot Fedora:

grub> set root=(lvm/system-root)
grub> linuxefi (lvm/system-boot)/vmlinux-... root=/dev/system/root
grub> initrdefi (lvm/system-boot)/initramfs-...
grub> boot

In Fedora:

/dev/sda2 is /boot/efi

mount -o remount,rw /dev/sda2
grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg

Do a reboot afterwards