I'm runing Linux Mint 19 on a Lenovo z70 Laptop. After shrinking my Windows volume so I can give my linux volume more space, I opened Gparted to find it more complicated than I'd thought. I want to give /dev/sda9 (my root partition) 220 GB from the unallocated drive. Here's a screenshot: (the image uploaded wont let me select photos so I used imgur) https://i.sstatic.net/N6uyM.png
EDIT It seems like I can shrink my Windows volume even more: https://i.sstatic.net/RpGtN.png
So I want to shrink it down to that size and then put as much storage as I can to my sda9 drive. When I select resize, however, the most it will let me add is aprox 10 GB. What I want to do is add 400 GB to the storage of my root directory. I'm not sure how to do this and I'm asking here because this isn't something I'm comfortable messing around with excatly. Thanks for your patience since I'm a newbie with linux and partitions.
gparted
screen-shot shows that you are trying to edit a running partition. You need to use a Live Boot disc: you can then expandsda9
above and below.