from another drive or from an OS X installation disk.
You cannot format or partition a drive from which you are booted.
Once you have booted the Mac, use Disk Utility to format the drive as a single partition, Mac OS X Extended (journaled) and you will be free to install OS X on there.
If you do not have another drive or OS X media to boot from, boot into Recovery mode, hold down the "R" key at the chime and use Disk Utility from there. Once done, you may need to reboot back into Recovery and allow OS X to be downloaded and installed.
If you have an external drive or a flash drive of 8GB or larger, you can make a boot disk from it by following the instructions at:
Hope that helps
"The startup disk must be formatted as a single Mac OS Extended (Journaled) volume or already partitioned by Boot Camp Assistant for installing Windows."
Ok here is the deal and the end goal i am trying to achieve, I had a windows partition i thought i deleted it a while back, to come to see i still have the HD partitioned. when i try to run boot camp i get the above error message. My end game is to erase everything from the HD and set the laptop to factory settings with out using time machine with 1 solid partition so that i can after re partition some space for windows. Any help would be awesome, and am very grateful to anyone willing to shed some light on the subject or direct me to the right place to have this sorted out. Again thank you for your time and efforts