File recovery wipe - Clearing data from hard drive

File recovery wipe - Clearing data from hard drive 

Clearing data from hard drive 
Question:I am 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: www.philly.com