Mysterious second disk called 'ErasedDisk'

[Rocket Mole]

How the hell do i delete this i am trying to get bootcamp working but the assistant either says my startup disk is not journaled, which it is, or i can only have 1 disk image...

PLZ HELP

Edit: this is the error message

The startup disk must be formatted as a single Mac OS Extended (Journaled) volume or already partitioned by Boot Camp Assistant for installing Windows.

 

[wrldwzrd89]

Go into Disk Utility. Select the device (not the 2 partitions in it, called Macintosh HD and ErasedDisk). Go to the Partition tab. Click ErasedDisk. Click the minus button. Click Apply. Then, drag Macintosh HD down to fill the newly open space. Click Apply once more.