Hi, i have a notebook with preinstalled Windows 8. i installed Kali, in the installation it didnt see any other OS, so i checked grub to mbr. After installation there was no Windows 8 option to boot. I had tryed with boot-repair, when i rebooted windows 8 appears but i was unable to boot, it writes "uknown filesytsem'. boot-repair added following code to grub.cfg

menuentry "Windows 8" {
insmod part_gpt
insmod chain
set root='(hd0,gpt1)'
chainloader /EFI/Microsoft/Boot/bootmgfw.efi
}

how can i repair my windows 8? Thanks