Ubuntu – Is GParted a good tool for resizing an NTFS partition

I think Avinash Raj answered most of this question in the comments, but I'll go ahead and write an answer just to square it off.

In your screen shot Gparted has locked the partitions of the drive (sda) because you are using the partition sda1 (/) to run Ubuntu and Gparted.

To edit the partitions on sda you will need to boot a live cd. When you do this the partitions will not be locked and Gparted will allow you to resize them.

You will have to right click the linux-swap partition and select swap-off to move that partition when using the live cd.

As far as booting the Live cd goes, try pressing: Esc, F1, F2, ..., F12, Del. when the computer is starting. Just run your finger from Esc to F12 then Del (delete). That's the lazy way of doing it. It usually brings up the boot selection screen for me. The alternative is reading the boot screen or the manual for the computer.

I can't explain much for LVM partition, but here's the generic steps.

I do understand that the key icon next to partition indicates that changes can't be made, but how exactly to fix that?

First, you need to unmount the LVM partition.

1. In GParted, select or highlight the row containing /dev/sda5
2. In the menubar, select Partition > Deactivate

GParted will rescan the partitions and the key icon will disappear.

Next, to shrink the LVM partition.

1. In GParted, select the same row i.e. /dev/sda5 again
2. In the menubar, select Partition > Resize/Move

A small dialog will appear, where you can resize the partition by dragging the left/right arrow in the top rectangular box representing the partition. Or, you can specify the partition size in mebibytes (MiB) by using the spinner (up-down control).

Additional steps may be required, which I don't have experience.