I decided to partition my hard drive to install Ubuntu on a 20 GB partition, but I want to get rid of that. However, for some reason, when I open Disk Utility it shows the screen like in the first screenshot, with apparent hard drives Macintosh HD, Recovery HD, BOOTCAMP (although I've never used that), disk0s5, disk0s6, and disk0s7. When I try to delete one, it shows the screen from the second screenshot, "Partition failed with error: Unrecognized file system". Also, when I try to erase one, it mounts it and it appears on my desktop. I just want to have Macintosh HD taking up my full 250 GB. Any help would be great thanks. EDIT: I ended up calling Apple Care. If anyone else here is trying to figure it out, they told me to backup then format my hard drive, install Snow Leopard via the disk that came with the computer, redownload Lion from the Mac App Store, install it, then run Migration Assistant to move my stuff over.