[Slick]

Do not attempt to format/rewrite by yourself to clear a harddrive. Use the software. The software completely writes 0's , 1's, random, etc over the entire harddrive in several passes. Don't be surprised if it takes several hours to complete the wiping. Most software allows you to set the number of passes. There are those who say that they can recover data from such wiped harddrives, but without getting specific here, I can say that this method is used by many "companies" in the world to destroy sensitive data - and it is a very secure method.