Is it possible to use an Ubuntu Live CD and run GParted to partition a my HDD (including the partition that is usually mounted on a given system)?

I'm encountering a problem with my HDD's partitions and can't resize it. I've described my problem and my system here: https://askubuntu.com/questions/89427/gparted-0-3-encounters-problem-with-file-system-and-wont-resize-partition.

Now, from a more general perspective, I was thinking on whether it is possible to use an Ubuntu Live CD and use GParted in a live session to possibly go around that problem. Is that possible? I made a separate question as I'm interested in the possibility independently from my current problem.

You see, I only have one partition and that's mounted. When I use GParted through Ubuntu I don't get any error reports (unlike the case reported in the question linked above).

Thanks beforehand.

Yes, you surely can..it is the easiest way to partition hard disks. Here are instructions on how to do it with Ubuntu:

https://help.ubuntu.com/community/HowtoPartition

Please, note that, if you want to format, delete or resize a partition, the drive must be unmounted before doing it.

It would also be possible to simply use the GParted Live CD as well.

http://gparted.sourceforge.net/livecd.php

On my linux systems, I actually skip using the CD or USB and simply use the from Hard drive option. So long as you use the "To RAM" option on your boot line, the hard drive is completely re-arrangeable when you are in GParted's environment.