Resize Zorin partition in dual boot

Hi,
I have got a 256 Gigabyte SSD hard drive split into some partitions. Two of them are Windows 10, the others Zorin and Recovery. One of the Windows 10 partitions has got some free space and I shrunk that partition. Now I have 20 gigabytes of free space but I cannot make the Zorin main partition larger (the two partitions are under the extended partition). Even gParted does not work (I used it in Zorin live so the partitions weren't in use): it shows the empty zone on my hard drive but doesn't let me make the partition bigger...
How can I fix this? I'd rather not install Zorin again as my Internet connection is very slow and unstable and I have installed updates and softwares. In the main Zorin partition I've got 14 gigabites.
Thank you!
I'll upload the image of the disks in the attachments.

OK, there are a couple of things here.
Firstly, to enable resizing a partition in GNU/Linux to make it bigger you have to have enabled LVM (Large Volume Management) in order to expand a GNU/Linux Partition. So if you did not enable LVM there is no way you can sort it out I'm afraid. Also looking at your partition management the allocated space for Zorin appears quite frugal and if you allowed Zorin to install itself in 'auto' mode, that can also lead to other issues. You should always manually create your Zorin OS installs where possible and I can appreciate Windows can sometimes think it is under threat if there is anything it does not recognise. The other thing that has to be considered is where is the boot (GRUB) been placed for Zorin to boot or did you use NeoSmart Technology's EasyBCD? What I would like to see is an EFI implentation at point of install for Zorin like Makulu LinDoz 15 does which actually tells you want you need to create (ESP in EFI) for it to boot on an EFI enabled motherboard. The other thing is to create a GPT boot partition for Zorin but that is beyond my current skill set.

Thank you, I will try what you said and update this topic ASAP.

I think, then, there is no way I can resize the partition. I'll try with Partition Magic but I doubt it will work

Like I said, a standard install will only allow you to shrink a GNU/Linux partition/volume - LVM enabled during installation allows you to resize either way. I have never personally had to use it, choosing to manually create partitions and an issue that can sometime rear its head when LVM has been deployed.

https://askubuntu.com/questions/693683/ ... -to-intern