My friend has recently tried to install Linux Ubuntu on his Macbook (i was at the same time) however the install didn't work, somehow it never actually installed it on the HDD. So we gave up and now when he went to go re-partition his HDD back into one for OS X, the disk utility app wont actually do anything and just hang there. Any help would be great. I myself had no problems with re-partitioning my HDD back to one. Here is a screenshot of the Disk Utility window. Any help on how to get this work would be great.