How to “un-partition” the MACINTOSH HD into one big hard drive

disk-utilitypartition

So I was messing around on my computer (it has a 250 gigabyte hard drive) and thought,"hmm I wonder what happens if I partition off 75 gigs of this". believe it or not, it partitioned off 75 gigabytes on my hard drive, so what's the problem? well I have no idea how to make it one big single 250 gigabyte partition again. I tried everything, I did the minus on the partition, I did the slide, I repaired with disk utility, same thing with disk utility from the restart CMD+R, and spent hours on the internet looking for a solution. Is there anyone who can help me here?

Best Answer

You can not do this on an active partition. You need to boot into Recovery Mode which will let you delete the unwanted partition and resize the main partition. Select the whole drive then the Partition tab.

http://support.apple.com/en-us/HT4718

PS Make sure you have a Time Machine backup before doing anything.