

I've went into Terminal, and typed: diskutil list When I try to expand the partition to fill in that extra space, and click "Apply", I get the error: When I go into the Partition tab, I have one partition, and it's 275.44GB out of my available 320.07.

When I click on the Mac HD (which is named "320.07 GB Hitachi HTS545032B9SA02 Media"), and then went to the Erase tab, and clicked "Erase." and I get the error: I have the original Mac installation disk in the computer, restarted the computer, and got into the Disk Utility by holding command + R, while it was restarting. I'm having trouble erasing the Mac hard drive though. I've been having issues with my computer constantly restarting after updating to Yosemite, so I'm trying to restore my computer back to factory settings (snow leopard) and going from there.
