See http://superuser.com/questions/94921...r-from-windows which gives a really good answer on how to repair your MBR (Master Boot Record) that was destroyed when you removed the source-partition containing the remainder of Grub's components that allow it to boot correctly.
Recommendation: First, document the answers from the article I've linked to, into a local file that you can pull up while you work on the system needing repair (or, alternatively, print it out if you only have the 1 machine). Second, download the 'Gparted-Live' ISO, and follow the instructions available online (Google search it) to create a bootable USB drive from the Gparted ISO. Third, after applying the MBR repair, boot up Gparted-Live and use it to make any resizing corrections to your partitions (if you would like to reclaim the space that was lost to installing Kali).
Finally... don't feel bad about this... just about everyone that's new-to-Linux makes this mistake at least once. Back when I started working with Linux back in 1997, Gparted didn't exist yet (or at least, I wasn't aware of it yet), so back then a mistake like this would have resulted in a complete loss of all data on the drive because it would have required a low-level-format to recover the drive to a usable state. Nowadays though, it's trivial to recover from this. Anyway, best of luck.
