Microsoft to end support for Windows XP
8 April 2014 Last updated at 13:33 BST
Microsoft is to end support for Windows XP software and will no longer provide official updates or bug fixes.
This is despite statistics showing that since XP's release in 2001, 20-25% users have stuck with the system.
Robert Schifreen, former hacker and security consultant at the University of Brighton, said users would need "common sense" if they continued operating the software.
He told BBC Radio 5 live's Adam Parsons: "Don't click on email attachments you don't trust, make sure your antivirus software is up to date. Microsoft's not doing the work for you."