How to wipe out data from old hard drive (File recovery wipe)

How to wipe out data from old hard drive  (File recovery wipe)

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

New Data Recovery and Security Technology for Windows Released to Computer Users across Asia, Europe, and Americas -  
This technology recovers or undeletes "lost" or deleted computer data of every kind including photos, audio and video from every kind of device including Hard Drives, CDs, cameras, floppies, Jazz drives, Zip drives, Flash media, Smart media, and others. Its features surpass earlier technologies.
Source: www.broadcastnewsroom.com

Recommendations for International Business Travelers and Laptop Users in Response to Ban on Notebook Computers in  
Absolute Software Corporation , the leading provider of patented, firmware-based, Computer Theft Recovery, Data Protection and Secure Asset Tracking solutions, announced recommendations for business travelers and notebook computer users traveling in and out of the United Kingdom, given the recent ban on laptops in airline cabins.
Source: biz.yahoo.com

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