A test version of Windows Vista reveals Microsoft is focusing on security, writes Richard Chapman

Children will hate Windows Vista. Like fresh air and leafy vegetables, Microsoft's new operating system has goodness that only a parent could love.

Parent, or system administrator - there are similarities between the two. Both need to keep the computer safe from prying hands and both have to deal with the whining that inevitably follows. Vista should make life easier for both by giving them far more control over what their charges can get up to.

But how is this new? A feature of XP is that you can create limited accounts to prevent users installing software. However well that works in the office though, it proves impractical at home. The younger members need to apply patches to their games every third day, and there's always some new media player skin to download.

Parents eventually cave in and give them administrator access. Being children, it is then only a matter of time before they click a link labelled "Unlimited Free Porn", little realising this is actually a Ukrainian expression meaning "Give me your computer".

Vista introduces powerful new tools to keep both child and system safe. While some are just nanny web-filtering features similar to those already available, others are more innovative and powerful.

One that children will absolutely loathe is that computer use can be limited by time. No staying up late in chat rooms for you! Unsupervised access without parental knowledge should become a thing of the past.

The big trick though is to make sure younger users never need to log on as administrators, and so be able to undo these settings. To this end, updates to certain games and so on can be explicitly allowed. Installing new software will still require administrative intervention, but instead of logging on, the adult will need only to enter their password, in what Microsoft programmers have taken to calling "over-the-shoulder" mode.

So what do the children get to compensate? Well, Vista is going to look distinctly cooler than XP. You will need a semi-decent graphics card to view the new "aero glass" transparent 3D features, but even without them Windows looks better than ever. For the first time it's as stylish as Mac OS, if not more so; it is, after all, black rather than white.

The interface is far more verbal and helpful than it once was. There is a lot more plain English and fewer indecipherable error messages. Old hands will find that tedious no doubt, but it's of obvious benefit to beginners.

Otherwise, they've kept things reasonably familiar. While in many ways Windows has been rewritten from the ground up for Vista, most big changes are to things that won't be perceived directly. The majority address security in its other aspects. Internet Explorer, for a long time the least secure of internet browsers, will suddenly become the most. It will now only run in a "virtualised" mode, meaning that any spyware it installs will be unable to harm the system as a whole.

Nevertheless, the Windows Defender anti-spyware program will also be built in, and the firewall will become a full affair instead of the one-way "firedoor" in XP. All of this extra security may begin to seem like overkill, but to compensate for its burden the core of Windows is supposed to become faster and more effective. This is exciting but it is too early to say if it's true as there are months of bug-fixing left to go.

One change that will be obvious to the user is the new file organisation system. Vista will automatically index your hard drive in much the same way Google indexes the web. Even text within images will be "read" and added to your database.

The idea is that instead of putting things in folders, you have virtual folders that are actually search results. Yes, it seems a bit bizarre to me too. Putting all your documents in one big heap and finding the one you want by searching sounds like keeping all your clothes conveniently on the floor. Perhaps the benefits become clear when you try it though.

And the thing is, you can. The current beta (test) version of Vista is available to download and install - as is a beta of the next Office suite. Microsoft has never released unfinished software to the public before (well, not officially. . .) but now they're allowing the likes of you and me to play with it for free and say what we think.

You are firmly warned not to go installing it over XP as an upgrade on the family computer. Beta software is never an upgrade. Set it up to dual-boot if you can, or use a machine you can spare. Short of wiping the hard drive - and therefore destroying everyone's files - there will be no way to "wind back" to XP when the time limit on the beta runs out or if you find it unusable.

Which you probably will. Vista is lovely and fresh, but like any other newborn it has a tendency to fall on its face. It isn't scheduled to be fully ready until the end of this year. This is the whole point of a beta release though - to see what goes wrong.

Windows has grown so vast and complex that there is no way even Microsoft can hope to spot all the bugs in-house. Showing it to the public and asking us to help out may seem a little odd, but it should lead to a better product and people do enjoy getting involved. Plus, it is fun to use the new software and experience the innovations for yourself. Microsoft could generate some genuine goodwill from this. Except among teenagers, of course. They're all going to want Macs now.