Before installing my current Ubuntu Oneiric Ocelot I was having 3 partitions on my hard drive (each in NTFS, and divided in 21GBs, 10GBs and 37GBs; approx 80GB). I put in the DVD in DVD-ROM and booted up with it. I was prompt whether to install Ubuntu side by current operating system (Windows 7) or totally remove all operating system. I choose to install side by the current operating system.

In next screen I took one of my partition (the one which was of 37GB) and totally formatted it. Then created a ext4 file system of 10GBs on it (here 'it' means partition that was of 37GB, not whole HDD). While proceeding I was asked to make swap partition so I created another swap partition of 5GBs.

I have Ubuntu installed, but now I am regretting about that 10GB, I should have done it more since I have much more space on my hard drive. And I have 22GBs of my hard drive useless (neither it is in ntfs nor ext4).

I want to increase the size of ext4 partition in which I have installed my Ubuntu; from 10GB to something more.