Installing Ubuntu 15.04 along side Windows 8.1

I have a 120 GB SSD in my laptop, and it runs windows 8.1 (not preinstalled). I have countless times dual or triple-booted the laptop when I ran Windows 7. Now I want to dual-boot it with Win 8.1 and Ubuntu 15.04, but Gparted and the Ubuntu installer wont let me re-size the sda2 partion for it to happen. I know I have about 35 GB of free space on it, and my plan is that Ubuntu should have around 20 GB, so that I still have room for various downloads and temp files on Windows.

Solution 1:

Have you tried using Windows to resize the partition? I have done this several times with Windows 8.1 and it works very well. It will tell you, if resizing is not possible.