unallocating or freeing some space to install another OS

Question

I would like to install another OS besides Ubuntu for this I need to have some space but I cannot find how to unallocate space how to do it.

Answer 1

Using Gparted you can accomplish your task. This need to be done from either the Ubuntu LiveCD, or Gparted LiveCD, since the drive has to be unmounted. Once you boot from the CD, and run Gparted, you can re-size /dev/sda1 to what you want, and once done, you will have some unallocated space for you to use.

Right click on /dev/sda1 unmount first, and then re-size, as shown in the image below.

Answer 2

GParted won't let you modify partitions that are currently in use -- that's why all of your partitions have key icons next to them, to indicate that they're locked. You need to boot with another disk (a live CD or USB flash drive), such as the Ubuntu installer. Booted in this way, most or all of your partitions will be unused and so will be modifiable. If any arent't, you should be able to unmount them (or deactivate swap space, in the case of swap) and make your changes.