Data recovery software freeware - How to wipe out data from old hard drive

Data recovery software freeware - How to wipe out data from old hard drive 

How to wipe out data from old hard drive 
Iam planning to sell my laptop (Toshiba Satellite 2800 series, about five years old) and want to know how I go about wiping out my hard drive of any personal information. I've been told that just reloading the operating software (Windows XP) will do this, but I want to know for sure.
Source: feeds.baltimoresun.com

Adroit Data Recovery Centre announces free data recovery software 
Adroit Data Recovery Centre (ADRC), a provider of computer data recovery services, now offers free data recovery software for public download. ADRC hopes to provide this freeware which can be used by any one with a few simple mouse-clicks, said Felix Chang, director of ADRC.
Source: www.computerworld.com.sg

Protect data by wiping out hard drive 
Q: I am planning to sell my laptop and want to know how I wipe my hard drive of any personal information. Ive been told that just reloading the operating software (Windows XP) will do this, but I want to know for sure.
Source: www.dispatch.com