Victor Bom

I have a Dell latitude with an SSD of 256 GB. It came with windows10 which I replaced with Fedora25. I made backups with Clonezilla: all perfect. Now I have upgraded to Fedora27, but have bad experience with it. So I restored the old Fedora25. To my utmost surprise after the resore it came up with an empty windows10 system! The windows system occupies only 40 GB. The rest of the disk contains maybe the Fedora system, but it can not be booted. Apparently there is no GRUB restored? What can be done?...