Certainly you can wipe the whole hard drive clean using a bootable CD: I include instructions to do so using dban
(Darik's Boot and Nuke):"Darik's Boot and Nuke ("DBAN") is a self-contained boot disk that securely wipes the hard disks of most computers. DBAN will automatically and completely delete the contents of any hard disk that it can detect, which makes it an appropriate utility for bulk or emergency data destruction."
If you do not already have a suitable burning program for writing .ISO images to disk ...
Download and install ImgBurn
(be sure to un-check the box agreeing to install the Ask toolbar): Choose "Write image file to disc
". The CD will be bootable.
Boot from the CD, and with ONLY the one hard drive connected to the system ...This will completely wipe ALL drives connected to the system!
at the prompt and press the <ENTER> key.
Allow to complete.Be patient: It may take some considerable time, depending on the size of the HDD.