Are you a casual computer user who wants a streamlined security software experience? Or are you a dyed-in-the-wool computer pro who wants access to every configuration option, security alert, and log- file entry?

With BitDefender Internet Security 2011 ($50 for a one-year, three-PC license as of 12/2/2010), BitDefender's goal is to cover you either way: Unique among security applications, it offers three different user interface views, one showing the absolute basics, another an intermediate view with a moderate amount of information, and third, an expert view with everything laid bare.

We expect most users will find the basic view too basic, while true novices may have difficulty finding the option to immediately scan their PC (it lurks beneath a large box labeled "Security"). The intermediate view is unique, reminiscent of an icon-based smartphone interface, with a series of boxes where various "tools" ("Update Now," "Configure Firewall," and so on) can be arranged by the user, much like app icons on an iPhone. And then there's the overwhelming expert mode, where I spent most of my time, if only because it offered the best access to advanced configuration options.

Organization could be better here--if nothing else, we'd appreciate the option to run a scan from the main dashboard without digging into the tabs--but on the whole, it isn't too much trouble to find what you need.

BitDefender's overall protection levels are very good, but short of the topmost tier of products we reviewed. In our examination, the suite stopped 22 of 25 real-world attacks and turned away 97.5 percent of known malware in traditional detection tests. Those figures sound good, but top products blocked 24 real-world attacks, and hit 99 percent or higher on the latter measure.

BitDefender excels in the realm of avoiding false positives: It had absolutely none in our tests, and it tied with PC Tools Internet Security as having the best overall success at fixing infected PCs, removing active malware components in 80 percent of infections, and removing all traces of malware 70 percent of the time. Unfortunately, BitDefender has a serious sore spot when it comes to system speed: While on-demand and on-access scan speeds were acceptable, simply having BitDefender installed slows your computer down considerably: Of the 13 products we tested, BitDefender was third to last when it came to its impact on our test PC's performance.

We had other issues with BitDefender that merit mention. Registration and activation are required during install, and setup seemingly takes an eternity of clicking through screen after screen. We loved that BitDefender hunts for old security applications on your machine and can uninstall them for you, avoiding the headaches that can be caused by having competing antimalware software on one system, but having to reboot and start the installation from scratch after removing the old antivirus software was a nagging pain.

A bigger concern was how noticeably sluggish BitDefender was at everything from simply loading its management interface to running scans. Full system scans took well over an hour, and during one full scan our test computer crashed. We also weren't fans of all the oversized system tray pop-ups that BitDefender is fond of. The information they provided was never of much use and could safely be hidden from even an expert user.

BitDefender is something of a budget option, and while it has its issues--and its security capabilities could use an upgrade--it's still a good fit for almost any class of user.