Here I kept a record of taking a backup of windows recovery partition /dev/sdc1 and install Ubuntu in the partition.
I installed Ubuntu 14.04LTS on a portable HDD. It was working fine on the installing computer. But it did not boot up in another computer (in a library). The program called boot-repair mentioned that the linux partion is too far from the beginning of the disk(in the terms of cylinder). I am not sure it is really the reason why it failed to boot.
I did not want to change the partition structure. But 4GB is too small to develop a webcite. it was 40% occupied immediately after a clean installation. But in a coupled days it became 74%... And it seemed to become slower. a short freeze become aparent again.
This 230GB hdd is old and I probably will not use this hdd other than for linux and web development. So I decided to modidy the hdd. But just in case I took a backup of the recovery partition of Windows.