Cannot format disk, cannot select erase. PIC

[AdventurousJosh]

I'm trying to format my disk due to an error with boot camp. However, I cannot push the erase button as shown below. Anybody have any idea why this could be happening?

 

[r.j.s]

You cannot choose erase because you did not boot from the DVD ...

 

[DewGuy1999]

To clarify what r.j.s. said, you can not erase or format the disk your Mac is booted from. To erase/format the internal hard drive you need to boot from your OS X disc (CD or DVD), from there you can erase/format install the OS.