The big day has arrived. Microsoft Corporation (NASDAQ:MSFT) will officially end support for Windows XP after today, April 8. It raises fears of the “XPocalypse” of malware, viruses and bugs among millions of PCs that still run on Windows XP. The software giant has warned that users who don’t upgrade will face a “zero day vulnerability forever.” That means such users will no longer have any defense against hackers.

Microsoft windows XP

About 95% of ATMs run on Windows XP

Microsoft Corporation (NASDAQ:MSFT) released Windows XP in 2001. Soon after, the Redmond-based company said that it will support all its software products for at least 10 years after their release. In 2007, the company extended the support for Windows XP to April 8, 2014 due to its immense popularity. As the operating system reaches end-of-life, software tracking firm NetMarketShare says that Windows XP still runs on about 28% of all PCs as of January.

Windows XP is wildly popular among businesses. About 40% of enterprise users still depend on the 13-year old operating system, and they have been reluctant to upgrade. But the biggest threat lies before the world’s ATM machines as Microsoft Corporation (NASDAQ:MSFT) ends support to Windows XP. According to ATM supplier NCR, about 95% of ATMs worldwide still run on Windows XP as of January 2014.

Consumers will still be able to use XP as long as they want because the operating system won’t just stop working. But such users will be highly vulnerable to cyber attacks. That’s because Microsoft Corporation (NASDAQ:MSFT) releases security patches every month to address the newly discovered vulnerabilities. Microsoft spokesperson Ian Moulster said that even if you have an anti-virus, anti-malware product, your PC won’t be safe because your system needs to be secure all the way from the operating system up. Of course, anti-virus products will be helpful to some extent, but they can’t protect you if the operating system itself has flaws.

Windows XP was released in an entirely different world

When Windows XP was released, it was an entirely different world. Email wasn’t so common, Facebook Inc (NASDAQ:FB) didn’t even exist, and the Internet was not widely used. Unlike XP, the latest versions of Windows have built-in protections that reflect the modern technological world. Microsoft Corporation (NASDAQ:MSFT) is offering lucrative deals to Windows XP users to upgrade to Windows 7, Windows 8/8.1. But some consumers may switch to a different OS like Apple Inc. (NASDAQ:AAPL)’s OS X Mavericks or one of the modified versions of Linux.

Microsoft Corporation (NASDAQ:MSFT) stock ticked up 0.10% to $39.84 in pre-market trading Tuesday.