If you don’t have (or don’t want to use) USB device or RW-CD-ROM to install operating system, you can do that via hard disk. This post introduces a way to install OS by grub which is verified on Ubuntu Precise.

Download the operating system ISO file from Internet, for example:

wget http://releases.ubuntu.com/12.04/ubuntu-12.04.3-desktop-amd64.iso

You can download http://releases.ubuntu.com/12.04/ubuntu-12.04.3-desktop-amd64.iso.torrent and use Transmission BitTorrent Client to open it to accelerate the speed.

Move the ISO file to a proper place, which is easy to explorer, for exampe:

sudo cp ubuntu-12.04.3-desktop-amd64.iso /ubuntu.iso

Reboot you system and press SHIFT after BIOS check is done, then you’ll enter the boot menu to select operating system, press c to enter grub shell. Note that we need the / partition place for grub, which means that (hd0, msdos1) may be different in you computer, for me, I only have one hard disk, so it is hd0, you can double press TAB after you input (hd0,, the grub will list the partitions you have, then you can select the proper one.

loopback loop (hd0, msdos1)/ubuntu.iso
set root=(loop)
linux /casper/vmlinuz.efi boot=casper iso-scan/filename=/ubuntu.iso
initrd /casper/initrd.lz
boot

Then you will enter Ubuntu Live system, remebter to umount the isodevice before you click the Install icon on the desktop, press CTRL+ALT+T to open shell:

umount -l /isodevice

Double click the Install icon on the desktop, everything else is exactly the same as a CD-ROM, enjoy!

License: (CC 3.0) BY-NC-SA