I use Ubuntu 12.04 LTS and I have downloaded GParted to resize my partition space. Now, quite simply, I have stopped using WinXP, and I want to shrink that space and increase the space of Ubuntu. I also want to know what Unmounting does. If the following screenshot is of any use to you.
This is the screen I have. I have searched Google, and I have nearly lost hope trying to find the answer. Please help.