partitioning - Allocate free space to Ubuntu partition with 4 primary already existing?

I just made 120 GB of unallocated space from my Windows 8 partition to put into my already existing Ubuntu home (sda7) partition.

The problem is when I try to create new partition from unallocated it says

It is not possible to create more than 4 primary partitions

All I want to do is put that free space into my Ubuntu (to sda7).

sda2 - Windows 8 drive C
sda3 - Windows 8 drive D

Edit: So I run "Try Ubuntu", unmounted all partitions, and resized /dev/sda4 so unallocated space is not below sda4. But when I try to resize /dev/sda7 (which I want) it only allows me to resize for 7Gb or so, not all 120Gb I need.

To put that 120 GB free space into Ubuntu ( /dev/sda7) partition,follow the below steps.

• First you had to boot Ubuntu live disk.




• Click on "try ubuntu" option on startup and then open gparted from Dash.Make sure that all your partitions are unmounted.




• Right-click on the /dev/sda4 partition and then choose Resize/Move option to increase its size with the 120 GB unallocated space by dragging the left arrow to the extreme left.After resizing,apply the changes.




• Now your 120 GB unallocated space will comes inside extended partition and just below to the /dev/sda7 partition.




• Right-click on the /dev/sda7 partition and select Resize/Move option,now you can be able to add 120 GB unallocated space to your ext4 partition by dragging the right arrow to the extreme right.