Ubuntu only boots with USB plugged in

Question

I'm new to the Linux world so please bear with me! :-)

I installed Ubuntu via USB drive onto my hard drive. If I boot the PC without the usb drive I used, Ubuntu will not load. After booting I can unplug without any consequences.

I looked on the hard drive and there is a boot folder. On the USB drive, this is the tree contents:

/media/disk$ tree
.
|-- adtext.cfg
|-- boot.cat
|-- f10.txt
|-- f1.txt
|-- f2.txt
|-- f3.txt
|-- f4.txt
|-- f5.txt
|-- f6.txt
|-- f7.txt
|-- f8.txt
|-- f9.txt
|-- initrd.gz
|-- isolinux.bin
|-- isolinux.cfg
|-- ldlinux.sys
|-- linux
|-- menu.c32
|-- menu.cfg
|-- po4a.cfg
|-- prompt.cfg
|-- splash.png
|-- stdmenu.cfg
|-- syslinux.cfg
|-- text.cfg
|-- ubnfilel.txt
|-- ubnpathl.txt
`-- vesamenu.c32

Am I correct in my assumption that the boot aspect is associated to the USB drive? If so, how do I get it to boot without the USB? I'm guessing copying into some location and modifying grub?

Answer 1

sudo fdisk -l
# identify your hard drive e.g. /dev/sda 
sudo grub-install /dev/sda

That'll do it. :)