Clean Exit Guides
Boot to the CleanExit DVD (by changing your boot order).
Once fully booted into CleanExit, enter your name and serial number into the boxes provided and select Activate.
Please note: If you have one internal drive you will need CleanExit; if you have more than one drive then you will need CleanExitPlus.
The internal hard drive will be set to erase within 10 seconds, you can stop this without any data loss before then, but if it continues to run, CleanExit will securely wipe all existing data.
Once it is complete, the drive will be erased with no possibility of the data being retrieved.