Lavasoft's Ad-Aware 2007 Plus is the paid version of the popular scanner Ad-Adware 2007 Free. For the US$27 price, you get automatic signature updates, scheduled scans, and real-time protection features not included in the free product. But despite its sleek interface and easy-to-configure controls, Ad-Aware Plus failed to meet basic expectations when pitted against adware, spyware, and rootkit threats.

At the time we tested it, Ad-Aware 2007 Plus 7.0 was not available for Windows Vista, so we tested it on a Windows XP machine. The scheduled release date for Lavasoft's Vista version is August 31, 2007.

In tests performed by AV-Test.org, Ad-Aware failed to detect nine of our ten active spyware samples and successfully disinfected only the Registry entry (not the file) of the one piece of active spyware (password stealer QQHook.A) that it did detect. While it uncovered all ten active adware samples, it disinfected just 35 percent of files and Registry entries. Presented with a batch of more than 110,380 inactive adware and spyware samples, the program's on-demand scanner detected less than 2 percent of them. Ad-Aware 2007 Plus doesn't offer rootkit protection.

The program's behavior-based blocking of critical system changes was better than its signature based scanning, but not perfect. It stopped additions to 'Run' keys HKCU and HKLM (Registry keys that the most common malware threats target), and it detected changes to the Internet Explorer startup and search pages. On the other hand, it failed to detect Hosts file changes (which can redirect an URL to a malicious site) and additions to the startup folder.

Ad-Aware is easy to install and navigate, and it comes with a feature called TrackSweep that erases browser surfing history from Internet Explorer, Firefox, and Opera. But the software's two-pronged software design creates needless complications. You have to configure the Ad-Watch component, which handles real-time monitoring and proactive protection, separately from the rest of the program, and Ad-Watch drops a second icon onto your desktop. It almost feels like a second piece of software. Also, the Sweden-based company does not offer telephone support to U.S. users.

Its real-time protection makes Ad-Aware Plus a definite step up from the popular freeware version. But its lackluster performance would send us searching elsewhere for antispyware protection.