Erasing Hard Drive Process Has Frozen, What Do I Do?

Reboot/Power down, then...

"Try Disk Utility

1. Insert the Mac OS X Install disc, then restart the computer while holding the C key.

2. When your computer finishes starting up from the disc, choose Disk Utility from the Installer menu at the top of the screen. (In Mac OS X 10.4 or later, you must select your language first.)

Important: Do not click Continue in the first screen of the Installer. If you do, you must restart from the disc again to access Disk Utility.

3. Click the First Aid tab.

4. Select your Mac OS X volume.

5. Click Repair. Disk Utility checks and repairs the disk."

http://docs.info.apple.com/article.html?artnum=106214

Then try a Safe Boot, (holding Shift key down at bootup), run Disk Utility in Applications>Utilities, then highlight your drive, click on Repair Permissions, reboot when it completes.

(Safe boot may stay on the gray radian for a long time, let it go, it's trying to repair the Hard Drive.)

When you get this going again, there is no need to do a 7 pass zero. If you are giving the computer away, unless it falls into the hands of the NSA, or there's a chance it will fall into the hands of someone with an electron microscope and the skills to use it, a one pass zero will be more than adequate.