I have installed windows 10 in one hard disk and in another ssd I have ubuntu 17.04 installed. Grub was installed in the drive where windows is installed. Basically the windows MBR got replaced by GRUB. Now I want to format my windows drive and reinstall windows 10 without disturbing the ubuntu installation. But if I do this then the grub will be gone. How can I recover the grub menu like previous without disturbing the ubuntu installation. Please help. I am a bit skeptical how boot repair will work. Since my hard disks are different will it be OK if I use the windows installer to format the ssd and install windows in it or is it better to use GParted to create a NTFS partition and install windows in it. will the boot repair replace the windows MBR or will it install GRUB in the partition where ubuntu is installed. These are the few questions which I have. I really don't want to reinstall ubuntu again.
It might not be what you want, but you could avoid using GRUB altogether by installing EasyBCD on Windows and adding Ubuntu to Windows Boot Manager.
Take a look here :