To be precise, I'm trying to install Debian 8 (Jessie) which at the part where it installs GRUB bootloader gives the error GRUB installation failed.Based on my Googling I found that I could install it through Execute a shell using a network connection. I'm using a wireless network, but I can't connect to it.Basically I created a bootable USB, extracted the debian-8.8.0-amd64-DVD-1 onto it and then continued dual booting my Debian with my Windows 8.1. But I am still stuck at GRUB installation failed.Any ideas? 
GRUB bootloader installation failed
linux;debian;grub