If you're the kind of web user who's already paranoid about companies stalking you online, Windows 10, the latest operating system from Microsoft, may just tip you over the edge.

It expands personalisation not just to your web browsing or phone usage habits – something Google already does to the Nth degree through Chrome and Android – but to your entire life across Windows-enabled devices*, both online and offline.

At the heart of it all is Cortana, Windows' answer to Apple's Siri and Google Now. Microsoft promises she is the most personal voice-activated personal assistant yet.

Cortana can read and store the contents of your emails, text messages and other apps, as well as location data, contacts, search history and calendar.

Ask her just about anything and she will trawl your personal data and apps for answers, as well as searching the web through Bing.

Siri and Google Now already do this comprehensively on mobile, but they are not fully integrated with a desktop operating system – yet.

The introduction of Windows Continuum – Microsoft's answer to Apple's Continuity/Handoff​ and Samsung's Flow, which allow for seamless transition of activity between branded devices/operating systems – makes this all the more potent.

But while this is all in pursuit of servicing you, the user, it may have the potential to backfire.

Take this, for example: you don't have to tell Cortana where you live or work – she'll figure it out herself, based on when and where you habitually use your Windows devices.

Now just imagine you were having a marital affair, and Cortana accidentally let slip as to your whereabouts the previous night. Oops.

Of course, you can choose to turn Cortana off entirely, periodically or permanently, or tweak the type of data she's privy to, but is this really something a busy person will remember to do? Besides, that would be largely missing the point of Windows 10.

Cortana won't be launching in Australia with Windows 10 just yet. A localised version, voiced by an as-yet-unidentified Australian actress, is due to be available through the Windows Insider beta testing program this winter, we're told.

In the meantime you can set your Windows PC to the "United States" region and have a play with the US Cortana – but be warned, she does struggle with the Australian accent.

Let's get Started!

Microsoft, to its credit, has taken on board what was largely negative feedback about Windows 8, and has brought back the beloved Start menu – sort of.

Windows 10 still has the live tiles we first saw in Windows 8 but has also reinserted a list menu alongside it, which features frequently used and recently added apps, settings, power options, and an option to view all apps in an alphabetical list.

Flexible moves

There are a bunch of new productivity tools that are here to please.

The Snap feature, which allows you to snap two apps into a split screen, is back and better – you can now snap into quarters.

You can create multiple desktops, too – handy if, for instance, you're skiving at work with Netflix and need to quickly switch back to "work mode" as your boss walks past. You can't have the same app open in both desktops, though.

I'm still not convinced by the dual desktop and tablet mode available on Windows tablet devices (I tested a beta version of Windows 10  on the Surface 3). I found the transition between these modes clunky in Windows 8 and while it's smoother on Windows 10, I still prefer to keep it in desktop mode most of the time, even when I'm not using the keypad, as it's more familiar and intuitive.

Also, that beloved Start menu disappears in tablet mode, reverting back to live tiles only. Why, I'm not sure.

Close to the Edge

Chrome has long since overtaken Internet Explorer as the world's web browser of choice, but Microsoft may be onto a winner with the brand new Edge.

It has some truly standout features which give it, well, an edge over rivals.

The first thing you notice when you open it is how delightfully clean it is. It's everything Explorer is not.

It allows you to save web pages and view them in a clean reader mode, minus the ads, effectively doing what apps like Pocket and Instapaper do, but without the need for a separate app.

You can mark up and share web pages, or cut out snippets of them, with highlighter and pen tools. As a tech writer who constantly reports goings-on around the web, I can see this coming in super-handy, particularly for interactions within our editorial team.

While I don't think anyone's expecting Edge to make Paint redundant (actually, that's not a bad idea?), I found these tools a little too basic. There's no text tool or paste function, and there's no undo function (Ctrl+Z), either. If you make a wrong mark, you have to select the eraser tool and then click on your mistake.

The short time I spent with Cortana also suggests she is unable to open web apps such as Gmail or Twitter via Edge, even when she knows your login details. She'll just search for the app web pages via Bing.

Watch this Window

There's already a lot to like with Windows 10; it's familiar enough for Windows 7 fans to embrace, while adding a bunch of useful features that are intuitive and improve the overall user experience.

There's a lot more to come though; namely, the Australian Cortana, but we can also expect further integration between Cortana and Edge to make the most of her potential. Hopefully Microsoft will improve on Edge's mark-up tools too.

Windows 10 also brings the Windows Hello face and iris recognition tool, which will fire up your device when you sit in front of it so you don't have to log in. But that requires a high-tech camera such as the Intel Real Sense 3D camera, which is, sadly, not on the current line of Surface devices, though some other non-Microsoft branded devices are compatible.

A few other things worth briefly noting with this software release are the rebranding of Xbox Music to Groove Music (which I have to say sounds a lot like the controversial Grooveshark music service, which folded following lengthy copyright battles); the ability to stream Xbox services from your Xbox console onto your PC; and beefed up Xbox graphics.

Should you upgrade?

Yes. It's totally worth it.

*Windows 10 for PC and tablet begins rolling out worldwide on Wednesday, and will come to Windows Phone soon.

This Melbourne-based writer travelled to Sydney as a guest of Microsoft to receive a briefing on Windows 10 and Edge.