Story image

How to erase data from an old PC or Mac

01 Feb 2011

This will be especially useful if you’re upgrading your office computers, and want to sell the old ones.
For PCs running Windows, Eraser (eraser.heidi.ie) is a free, open source tool which allows you to completely remove sensitive data from your hard drive by overwriting it several times with carefully selected patterns. However, some data is stored in files that are normally hidden, and you need to locate these files as well.
To do this, go to My Computer>Tools>Folder Options (in Vista, go to Organise>Folder and Search Options), then View>Show hidden files and folders. Then open the Application Data folder (‘AppData’ in Vista) and right-click to erase it. NB: the Eraser program may require you to erase files one at a time. Start with any named after heavily used programs or their developers (for instance, ‘Mozilla’ or ‘Microsoft’. If you use Outlook Express, the data is stored in a folder called ‘Identities’. Then you can wipe anything valuable in such standard, visible folders as My Documents.
Because of the volume of email stored in most computers, erasing all this can be a long, tedious task. To make it easier, create a new user account just for erasing data.
In Windows, go to Control Panel>User Accounts (in XP) or Add or Remove User Accounts (Vista).
See tinyurl.com/ygu5vh for advice on creating accounts in XP. Note your old account’s name, then create a new account and pick ‘administrator’ as its type. Log out of the old account and into the new one. In My Computer, go to your hard drive (C) and open Documents and Settings (XP) or Users (Vista). Right-click the folder named after your old account and select ‘Erase’. NB: this takes quite a while and is probably best left running overnight.
For Mac OS x 10.3 or later, see tinyurl.com/3yetdbo for advice on how to overwrite files sent to the Trash bin, to ensure they can’t be recovered, using Secure Empty Trash. For older versions of Mac OS, download Permanent Eraser from tinyurl.com/36ep7au.
To create a new administrator account in Mac OS X, go to System Preferences>Accounts. Again, note your old account’s name and create a new, administrator account. Log out of your old account and into the new one. In the Finder, go to your Mac’s hard drive and open its Users folder. Select your old account and use Secure Empty Trash or Permanent Eraser to wipe it.
Don’t forget to reload the original software before selling the computer.

How big data can revolutionise NZ’s hospitals
Miya Precision is being used across 17 wards and the emergency department at Palmerston North Hospital.
Time's up, tax dodgers: Multinational tech firms may soon pay their dues
Multinational tech and digital services firms may no longer have a free tax pass to operate in New Zealand. 
Spark’s new IoT network reaches 98% of New Zealand
Spark is the first company to confirm the nationwide completion of a Cat-M1 network in New Zealand.
WhatsApp users warned to change voicemail PINs
Attackers are allegedly gaining access to users’ WhatsApp accounts by using the default voicemail PIN to access voice authentication codes.
Robots to the fore – Key insights for New Zealand Business into RPA in 2019
From making artificial intelligence a business reality to closer ties to human colleagues, robotic process automation is gearing up for a strong 2019.
50 million tonnes of e-waste: IT faces sustainability challenges
“Through This is IT, we want to help people better understand the problem of today’s linear “take, make, dispose” thinking around IT products and its effects like e-waste, pollution and climate change."
Vocus & Vodafone unbundle NZ's fibre network
“Unbundling fibre will provide retail service providers with a flexible future-proofed platform regardless of what tomorrow brings."
IDC: A/NZ second highest APAC IoT spenders per capita
New IDC forecast expects the Internet of Things spending in Asia/Pacific excluding Japan to reach US$381.8 Billion by 2022.