MacBook Pro does not Boot from the DVD grey Screen

Hey Gys I need youre help,

I have Bootcamp on my MacBook Pro and there is a Windows Partition an a Mac Partition.

When I want to start the Mac OS X there comes a grey Screen with the Apple Logo and a circel which is turning.

Now i want to install the OS X new, and boot from the Install DVD of OS X.

I press the key "c" and after a while the same grey screen comes and i cant do no further action.

The Windows Partiton works well.

pleas help me !