I have a HP laptop that originally had Windows 7 OS on it, I partioned the drive and allocated 100gb (est.) for the ubuntu install. the install went fine i have ubuntu and windows 7 still on the computer. But I can not get the OS boot screen to show ubuntu as an OS. I can while start up pull up the start menu screen via ESC. Key and press F9 for Boot Device Options and get the boot manager screen and it lists... OS boot manager, Ubuntu (Hitachi HTS 543232A7A384), boot from EFI file, and Notebook Hard Drive... I can boot Ubuntu from this screen by selecting Ubuntu. But i would like to make it easier to access. The computer boot is not for myself otherwise it would not be a problem i would remove windows altogether. I would like to make it basically "User Friendly" if that's at all possible and make the OS boot screen show Ubuntu as a bootable OS as well as Windows 7. on the boot selection screen. Any help on this issue would be greatly appreciated, I've looked to see if i could find the answer and maybe i've overlooked something so here I am. Like i said i need it to be as user friendly as possible and force the user to choose windows 7 or ubuntu not send them into one or the other without them being allowed to choose. I can get any information you might need if necessary but i dont know exactly what you'll need other than what i've given. Ubuntu version is the 13.04 just so you know.
What you are looking for, is called Grub (bootloader). Bootloader lets you select the OS.
Boot your system using a live cd or live usb. Open Terminal. (ctrl+alt+t)
Find the parition on which linux is installed. Let say it is
Now we can install the grub.
Note in the above command it's sda and not sda4. Grub is installed, now update it.