Reader Steve uses a program called Vipre Premium to keep his PC secure. The suite offers anti-virus, anti-malware, anti-spyware, a firewall, e-mail protection--basically, the works.But Steve also runs Malwarebytes Anti-Malware. And Microsoft Security Essentials (though with real-time protection turned off). Steve's question: should he turn on MSE's real-time protection and "run it concurrently with Vipre?"Short answer: no. Definitely not. In fact, I'd say Steve is running too much security software as it is. And that's a common mistake.For starters, the Vipre suite is more than sufficient. I can see keeping Malwarebytes Anti-Malware on hand just in case some infection sneaks through, but if you're using the Pro version--which, unlike its freebie sibling, offers real-time scanning--then it's competing with Vipre. In fact, when you overlap security products like that, they can seriously impact system performance and even falsely recognize each other as being a threat.My advice: keep your security tools to a bare minimum. In fact, if you're running Windows 7 (which Steve is), you're already adequately equipped to handle the majority of security threats. Windows 7 offers a solid firewall, and its built-in Windows Defender should block most spyware and pop-ups.Meanwhile, Internet Explorer 9 provides robust protection against phishing, malware, and other browser-related threats. (In fact, some tests have shown it to be the safest browser, period.) Cap that off with Microsoft Security Essentials and browser plug-in Web of Trust, and you've got yourself a nearly bulletproof PC. (I speak from experience: that's my exact configuration, and I haven't had an infection of any kind, well, ever.)Bottom line: don't overdo the security software. Too much is not a good thing.Contributing Editor Rick Broida writes about business and consumer technology. Ask for help with your PC hassles at firstname.lastname@example.org, or try the treasure trove of helpful folks in the PC World Community Forums.