[P0ker]

Hey, so I've got a mid-2010 macbook pro with i5 and 4gb DD3. I'm currently dual booting Sierra and latest Kali, using reFIND for bootloader. What I want to do is to make another partition and install Windows 10 on it, however, I'm not sure if it's just a matter of inserting the CD and and just installing on said partition; I am pretty confident it'll mess up the bootlaoder.

How do I procede when doing this?

Thanks

[P0ker]

You've got to make a partition for Windows using OSX. without changing the size of Kali's partition.
Then, you hold the Option (alt) key down when you turn your mac on and insert the windows disk.
When you are setting up windows, pick the partition that you made on your mac side.
If you change the partitions sizes from the windows install disk, it will write over the mac partition.

I advice you to backup your content with an external drive before attempting this.

Hey, thanks for stopping by!

I did the partitioning and burned the Win10 image to a cd but when I try to boot it, it gets stuck at the very beginning on the blue windows logo. Any ideas?

[Periche]

Maybe try to change the bootloader. I used Clover when i tried Hackintosh my hp laptop and it worked. I'm not sure if this is a solution for you but you could try.