I've installed Windows 8.1 after Ubuntu 15. Now there is only one bootable OS and that is Windows 8.1. How can I recover Ubuntu 15 boot loader?
You can use
- Create an Ubuntu LiveCD or LiveUSB
- Boot into it.
- Install the program
boot-repaironto the CD or USB.
- Launch Boot Repair and choose the default repair. It should work fine.
(There is also a more complex method available which involves chrooting into your system, but I personally prefer this one.)
This should work. Just ask if you need any more help :)
To recover Grub (I'm supposing this is the original bootloader)
Boot through Fedora DVD or Red Hat DVD of Mandriva , not Ubuntu
Select Troubleshooting and then select Rescue installed system option
To the question "Do you want to start the networking" say no.
Once you get to the shell enter the following three commands: