Symantec's flagship security product aimed at the desktop has undergone a substantial - upgrade for 2006. The application blends a firewall, spam filter, virus and worm protection, email and instant messenger scanning into a single application and is designed to simplify the ever-more-demanding task of securing PCs.

The 30-minute setup procedure is relatively straightforward; the program prompts for a little information, then handles the majority of the decision-making and copying without intervention. Setup comprises copying the files to your PC, updating the definitions and application, and configuring basic security settings.

The yellow interface should be familiar to anyone that's ever used a Symantec product, and the layout has changed only minimally from previous versions. Most action takes place on the "Norton Protection Center" screen, which serves as a de facto home page for the application and houses links to the security components that make up the suite.

There's a heading under the Protection Center called Data Recovery, which is designed to monitor the status of backup applications running on the system. While Norton Internet Security 2006 had no problems identifying a running copy of Ghost 10, it failed to pick up a number of different backup applications running on other test systems, instead listing "No Coverage" on the Protection Center screen. While this error is no problem for experienced users that know what's running on their PCs, it could be a concern for the less tech-savvy who may be tricked into thinking there's a problem with their software.

When running, the suite is accessed via an icon on the taskbar that changes colour depending on security status. Pop up messages appear for any potential problems that may need your attention, but Norton has wisely kept the interruptions to a minimum - the software only alerts you for serious issues, like a virus hitting your desktop.

Many of the components of the suite have undergone minor changes and upgrades, but there's a significant improvement in the firewall application, which minimizes queries to the user and takes a much more automatic approach to creating rules. The previous version bombarded the user with request queries as applications tried to access certain ports, and it was daunting to inexperienced net surfers.

One handy new feature over the previous release is the Security Inspector, which is designed to review system-wide security settings and suggest ways of plugging potential holes. It looks into browser settings, Windows passwords, and patches and then prompts to make changes to take care of any concerns. It will fix Internet Explorer settings that it considers weak, but it won't prompt you to change Windows passwords - you'll have to do that yourself.

Unfortunately, the bulky software has a negative effect on system performance. Every test system slowed to a crawl during scanning, and there's a noticeable hit when opening files over a network or removable disk. You're best off scheduling the scan - which can easily take over an hour - to run when you know you'll be away from your PC; on a lunch break for businesses, or overnight for home users.

Protection against spyware, straightforward virus and worm scanning, and a browser restore function that stores - and monitors - browser settings in case of hijack round out a comprehensive, if pitifully slow, security package.