Warning: If you’re still running Windows XP, you just became an easier target for cyber thieves.

As of today, Microsoft will no longer provide technical support for Windows XP, officially marking the end of all security updates and bug patches for the 12-year-old vulnerability-ridden operating system.

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Should you choose to still run Windows XP on your PC -- some 20 to 25 percent of all enterprise users reportedly still do today -- you do so at your own risk. Your PC will no longer be protected from viruses, trojan horses, worms, bots, hackers and scads of other nasty threats. It’ll also be a bigger headache to run apps and connect to printers, scanners and other devices that don’t play well with XP, but that’s the least of your worries.   

In this situation, like most in life, doing nothing is the worst possible thing you can do. Here are your options, along with fast, (mostly) easy step-by-step instructions on how to execute them.  

First, check if your PC is actually running Windows XP. To do this, simply go to http://amirunningxp.com. If you are, this site will let you know and will walk you through what to do.

Decide if you will upgrade or stick it out with Windows XP. For the reasons laid out above, we suggest you upgrade to a newer Microsoft operating system. Ask yourself if you’d rather spend time, effort and money constantly tending to the vulnerabilities of your old XP system, or if you’d rather forget the hassle altogether and finally upgrade to the latest Microsoft operating system, Windows 8.1. And there’s your answer.  

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What to do if you decide to keep running Windows XP: Again, this is the least optimal option here. However, if you do keep running Windows XP, there are still several ways to boost your PC’s security, according to Gartner vice president and fellow Neil MacDonald. The world-renowned information security expert wrote a helpful blog post outlining 10 best practices to lower the risk of using the operating system “to a tolerable level.” Be sure to check them out.

Once you’ve done that, your next step should be to run all of Microsoft’s earlier updates, including the final one today. You should also disable your internet connection to reduce risks. If you must go online, make sure you steer clear of email and social media networks to avoid potential malicious software attacks. (What’s the point of going online then?)

Also delete older applications and remove administrative rights for every profile user on Windows XP to further reduce the risk of malicious software infecting your computer.

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Or, if you don’t want to deal with all of the above hassles to lower your risks but want to keep running Microsoft XP, your best option is to pay Microsoft to do it for you, though custom solutions and support aren’t for everyone and don’t come cheap.

What to do if you decide to stop using Windows XP:
Your two choices here are pretty cut and dry. You can either upgrade to the latest Microsoft operating system, Windows 8.1. (You might also consider opting for Windows 7, which some users, especially companies, prefer because it’s generally perceived as more trusted and stable overall than Windows 8.1, even if the newer version is faster.)   

Or, if your computer is too outdated upgrade, you’ll likely be in the market for a new one. Bonus: Shopping! Microsoft said on its support site that “very few older computers will be able run Windows 8.1,” but doesn’t define “older.”

To see if your current machine meets the necessary system requirements to run 8.1, download and run the Windows Upgrade Assistant. If it does, you're set up for an upgrade.

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Before installing a $119.99 Windows 8.1 DVD (good luck finding one – as of 1:24 p.m. EST, Microsoft was out of stock and Amazon only had three left) you’ll need to backup any existing files and applications that you want to keep to hard disks or an external hard drive, then wipe the complete contents of your hard drive clean.

If all of this sounds like Greek to you, check out Microsoft’s super detailed tutorial on how to upgrade from Windows XP to Windows 8.1. It’s a big help.

If your computer can’t upgrade to Windows 8.1, it’s time to shop for a new one.
PCs have come a long way in the 12-plus years since XP launched. They’re lighter, faster and relatively more affordable, and some PC makers are offering special deals just in time for XP’s curtain call.

It’s no surprise that Microsoft is getting in on the deal action, too. The tech giant is offering former XP users $100 off on “select PCs” priced at $599 and higher until June 15. But, of course, restrictions apply.

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Windows XP debuted on Oct. 25, 2001 and was succeeded by Windows Vista in 2007, followed by Windows 7 in 2009 and Windows 8 in 2012.