Unable to install Win 7 on Mac Pro Desktop

I'm not sure if this is the right spot to post this threat, but I am desperate for help! I used bootcamp and was able to make the partition and have it start installing windows 7... however when it says select the driver on which to install it... I am unable to do so because none of the hard drives appear. Someone please help! I will answer any questions that you may have that might assist you in resolving my dilemma.

Fond Regards,
Brian