I installed Ubuntu 12.04 (from a bootable USB) alongside my Windows Vista Ultimate operating system. Everything during installation went smoothly and at the end I got the message that Ubuntu is installed and I need to restart the computer which I did. However, when the computer restarts it automatically goes to Windows Vista and there is no option to load Ubuntu. Now the only sign of Ubuntu existing on my computer is that the hard drive size is 50gb smaller (which I allocated to Ubuntu during its installation). Can anyone please guide me what to change to bring the installed Ubuntu to life?
This problem is duplicate with no grub menu for 11.10 and 12.04LTS .
Boot with your USB plugged in. Enter the Ubuntu system.
In the terminal, type in
$ sudo grub-install /dev/sda
(if you get an error, replace sda with hda), and then
$ sudo update-grub
Reboot without the USB plugged in. You should see the grub menu now.