you can use CCleaner for that bro..
you can DL it from here:
CCleaner - Optimization and Cleaning - Free Download
it is freeware you dont have to purchase it.
after DL & Installation right click recycle bin.
Select Open CCleaner
Select Tools in the right side pane
Select Drive Wiper Tab
Select Hard Drive to Wipe. eg. C, D, E, etc.
choose Gutman then click wipe
or if you want an effective but expensive method. (note: it is not software based wiping)
keyword: demagnitizer (it will wipe the entire data on a HD with the correct settings)
reference:
Code:
http://www.x-magnet.net/Machinery/demagnetizer.html
http://www.tootoo.com/d-p21973731-Disk_Eraser_Disk_Demagnetizer_/
or create your own Home Made HD Demagnetizer Box.
prerequisite: TV with degauss Coil (not recommended sikma ka kung ma sayop ka)
waiver:
use at your own risk