If you’ve installed Windows via Boot Camp, and now want to delete it and restore the space to your main Mac hard drive, this brief tutorial will guide you through the steps to do just that.
It’s actually quite easy to remove the Windows drive and reclaim all the hard drive space, the only “problem” is that Apple doesn’t make it an obvious process.
NOTE: by deleting your Windows Boot Camp partition, you will of course be deleting all of the data on that partition. Make sure to back up anything on your “Windows drive” before you proceed. Your OS X partition will not be erased and you won’t lose any data from it.