Can't use Boot Camp with drive already partitioned
To do it the 'easy way', fully utilising Boot Camp, you need to start with one single volume on the Mac [ignoring the hidden volumes].

Boot Camp will then repartition for you &amp; set up Windows on that new partition. Removal is then just as simple, using Boot Camp.  

Boot Camp does more than just partition the drive, it sets Windows up in such a way that it is unaware it's being 'fooled' into thinking it's in charge of the drive.

Resist the temptation to ever change the volume structures any other way; tears will ensue ;-)

Best way to go right now would be to remove that extra partition in Disk Utility &amp; extend the main one back to the entire drive, then let Boot Camp re-partition in its preferred way.

It can be done other ways, but none of them are as simple.