I installed ubuntu on a windows machine, but after restart the computer automatically booted windows without showing me boot option. I think I might have installed my ubuntu bootloader in the wrong partition. I previously have sda1,2,3,5 and 6. I partitioned sda6 into sda6, sda7 and sda8. I mounted / on sda6, swap on sda7, /home on sda8. When choosing where to install bootloader on the bottom, I selected sda6, instead of sda, where my windows bootloader is. I wonder if I should choose that disk? And now how can I repair it? I used a usb to install it. I can lunch ubuntu directly from my usb, so I tried grub-install /dev/sda on the usb lunched version but it displays: cp: cannot create regular file `/boot/grub/915resolution.mod': Permission denied. Don't know what to do.
Btw, in which disk is my ubuntu kernel installed? thanks a lot.