Can’t extend C partition. How to make unallocated space “adjacent”

You will not be able to extend E: into unallocated space that is not adjacent to the partition, without doing odd things that are possible , but not practical (like spanning with dynamic).
You have 2 other partitions that will have to be "moved" to the ends first. There is partition software that could move the other partitions, then you could expand into the adjacent unallocated space.

Even using such software to move the partitions, that activity , especially with the different file systems, should be done only after you have a backup of all data on that whole drive.

The graphic view of the disk layout in the disk manager, would be handy to see here. In windows , with simple disk partitioning you can only have so many logical partitions in the extended spaces. There are times when very small Unallocated spaces are not visually shown in the grafic view.

So I eventually solved it like this:

1. Open windows command prompt with administrator privileges
2. Type diskpart and press enter
3. list disk and then select disk 0 (or relevant number) to select the disk
4. list volume and then select volume 2 (or relevant number) to select the volume
5. Then simply extend and this extended the D drive to fill the available space to its right!

I think the reason Windows couldn't do it from the Disk Management GUI is that it's inside an "Extended partition" and so there wasn't space inside that to extend D, without also extending the extended partition around it (marked in dark green). And clearly it's not clever enough to do this for you (although it can from diskpart!)