Kaspersky's latest software suite combines an anti-virus program with an internet firewall, parental controls and privacy protection.

It also incorporates defences against spyware, spam and all the other rogue programs that threaten the security of your computer and the information it contains. A simple setup program installs everything in one go and then sets off on a system scan that checks to see if the computer is already harbouring hidden threats.

Depending on how big the computer's hard disk is, and how full, the initial scan might take several hours, but subsequent scans are much faster because the program is bright enough to ignore files that haven't changed since the previous sweep. A control panel shows at a glance which types of protection are in force.

Three types of anti-virus protection are listed, for files, email and the web, but Kaspersky defines many other types of rogue programs and potential intruders under the catch-all description of virus, so these three modules actually protect against a wide range of threats.

Other control panel indicators show the states of the firewall, privacy control tools, spam guard, parental controls and "Proactive Defense" features. The latter keeps an eye out for unknown threats by constantly checking the host computer for evidence of virus-like activity.

Normally the program picks up viruses and other threats by referring to a database of known threats that is updated by the company each hour, the updates being downloaded and installed automatically.

Proactive Defense catches anything that slips through the net but unfortunately it also reported a lot of false positives – things that weren't threats, but the program thought they were – and leaves the user to decide whether the threats are genuine. Clicking for help takes you to Kaspersky's website, but all too often the information there is incomplete or too cryptic to be of use.

False positives also crop up in the anti-spam module, which protects any installed email program, but unless you're the sort of person who reads help sections in detail you might not pick up on the fact that it needs to be trained before it works properly. Without training it reported forty per cent of messages as spam the first time around.

Although independent tests and our own experiences suggest that Kaspersky Internet Security finds more threats than the competition, it can cause a certain amount of head-scratching unless set up properly. Turning on parental controls, for example, branded every user as a child, keeping them from visiting any websites until the option was changed.

For those prepared to put in the time, this program provides peace of mind and the highest levels of protection. It can be customised precisely and there are good discounts available online.