GParted can't make new partition by resizing

Solution 1:

WARNING: BACKUP ANY IMPORTANT DATA BEFORE MODIFYING PARTITIONS!

/dev/sda5 "looks" full (because it's not a regular partition)

• you can't make it smaller unless you delete some stuff
• you can't make it larger because it's already at its largest size, based on disk size
• it's in an extended partition
• there's no room to add a partition for Windows
• its part of a lvm set

Your disk partition /dev/sda5 is part of a lvm set, and as such, you need to use lvm utilities to manage it. Install system-config-lvm, and start Logical Volume Management from the Unity dashboard to resize lvm partitions. Or use the Disks application, which is already installed in Ubuntu, and on the Ubuntu Live DVD.

Logical Volume Management

in terminal:

• type sudo apt-get update
• type sudo apt-get install system-config-lvm
• quit terminal
• open the Unity dashboard
• type lvm
• start Logical Volume Management

alternative Logical Volume Management

• it was just pointed out that the Disks application supports lvm directly. Just start it from the Unity dashboard. It's also available on the Ubuntu Live DVD. It may be even easier to use than Logical Volume Management... but install it anyway, 'cause it's kind of fun to see it visually.