[ubuntu] Windows 10 not appearing in grub

Hi,

I have upgraded windows 10 32bit to windows 10 64bit later UBUNTU 15.10 32bit to 64bit (in non uefi mode i dont remember how I have upgraded windows 10 , i mean whether uefi or not).

After loading ubuntu no os was seen in grub (it started in grub rescue mode)
later I logged in to system with live ubuntu(usb stick) and installed boot-repair and executed it.

After rebooting I could see only ubuntu 15.10 in grub.

How to get the Windows10 in my grub menu??

Thank you.