If you're still running Windows XP or Windows Vista, for whatever reason, you really need to upgrade. Microsoft and other companies are rapidly abandoning these operating system, and no longer support users who use Windows XP, and increasingly users of Windows Vista. This includes Windows security and stability updates, antivirus signatures, program updates and even new hardware peripherals!
PCs running Windows XP have not been truly protected for more than a year. Microsoft on April 8, 2014 officially ended support for XP, meaning it stopped rolling out security updates for the aging OS. Microsoft will also stop supporting Windows Vista by April 2017. To add to this, companies like Google, Symantec, AVG, Apple, Java and Adobe have already ended all upgrades and support for their hardware and software services for Windows XP and Vista PC's.
Microsoft has been pleading with customers to upgrade to a new OS for years, so you can't say you weren't warned about this. If you're still on XP (or Vista), perhaps now is a good time to finally upgrade. Windows 10 has been released for a while now, and is the operating system best suited to home and business users today...better still, it is free for Windows 7 and 8.1 users!
Adapted from: http://au.pcmag.com/windows-10-preview-release-date-news-features/35546/news/still-using-windows-xp-stop-it-dummy (12/04/2016)