Unlike its predecessors, Windows 10 isn't expected to be superseded by a new release but rather upgraded over time, with Microsoft bolting on new features via regular updates - which home users won't be able to refuse.
That means even if you don't like Windows 10 now it should get better over time. That's good news - as, at present, Windows 10 seems more like an operating system with promise, rather than a must-have.
Of course, many of these criticisms should be tempered by the fact Windows 10 is free to the vast majority of users. As widely covered, anyone running Windows 7 or 8.1 will qualify for a free upgrade to Windows 10, which, providing they meet the system requirements, will be available via Windows Update.
The desktop is back
While the desktop never really went anywhere in Windows 8, Microsoft did its best to hide it - alienating a host of users who took against Windows 8's touch oriented Start Screen.
Mindful of that backlash Microsoft is stressing the familiarity of Windows 10, pitching it to Windows users as a comfortable pair of shoes, albeit with shiny new buckles and springy soles.
Windows 10 boots into a desktop whose layout will be familiar to any longtime user of Windows and which once again features the Start Menu - the removal of which caused consternation in Windows 8.
Windows 10's Start Menu looks similar to that found in Windows 7 but with part of Windows 8's Start Screen welded onto the side.
The left-hand side of the menu shows links to File Explorer, your most-used apps, the shutdown menu and a system settings menu - which seems designed to be simpler for novice users than the control panel. The right-hand side is dedicated to Live Tiles found in Windows 8 Start screen. These tiles are link to apps like Weather or Mail but can display dynamically updating information - such as the latest forecast or new messages. The Start menu is customisable - with users able to pin apps as tiles, or to the Taskbar. The menu also includes an alphabetical 'All apps' list, which can be brought up by swiping up on the lefthand side of the screen. In Tablet Mode the Start Menu resembles Windows 8's Start Screen - filling the screen with Live Tiles.
It's also more apparent how to interact with apps from the Windows Store in Windows 10. Such apps now start inside a window and have a settings menu that can be accessed via a hamburger-style button, rather than being hidden away in a Charms bar as in Windows 8.
Swapping between programs feels easy, thanks to Windows 10 Task View, which now gets its own button on the Taskbar. Task View shows you thumbnails of the apps you've got open and allows you to use keyboard shortcuts to jump between apps and virtual desktops, as well as letting you drag and drop apps onto new desktops.
There are some confusing quirks, however. Call me stupid but when a menu says 'All apps' I expect it to show all the apps on the computer. But it doesn't. Notable omissions include WordPad and Internet Explorer, despite both shipping with Windows 10. For a while I thought the only option for writing documents was OneNote, a role it is ill-equipped to perform. It could be a pre-release bug but it was true of the build closest to the day one release. That said finding programs is easy, thanks to the Taskbar's search box, which can be used to look for files and software stored both locally and online.
Settings and notifications for apps and the system are easily accessible via the Action Center, which sits at the bottom right of the screen on the Taskbar.
As a longstanding user of Windows I was able to use Windows 10 without issue and I imagine that anyone with a passing acquaintance with Windows will comfortable using this latest OS.
Windows 10 feels also feels responsive to use and quick to load, booting to the log-in screen in 10 seconds. Admittedly I tested it on a high spec machine that also ran Windows 7 well but the new OS certainly doesn't bog down, even when I had 10-plus apps open. Applications were quick to load and there was no lag when opening, closing and moving windows. When the screen is in standby mode Windows 10 can also stay online continue downloading updates and messages.
Just like in its mobile OS, Microsoft has put its virtual assistant Cortana at the heart of Windows 10.
Summoned by clicking the search box in the Taskbar or, if enabled, by saying 'Hey Cortana' - Cortana is both far more and far less capable than a real life assistant.
Cortana has various abilities. It can answer simple questions, such as the distance from London to Edinburgh. Cortana can also remember various things about you if you let it, such as where you live, work and your interests. This allows you to make your queries less explicit. For example, you can ask for directions to London and it will set your home location as the starting point. However not all of Cortana's features are as fully fledged as competing services. For example, the journey options are more limited than those offered by Google, where typing in 'Location a to Location b' will give you turn by turn directions for car and walking, as well as public transport times. Cortana also use what it knows about you to recommend things you might be interested in, such as restaurants at lunchtime or events in your area. You can also dictate emails to Cortana pretty quickly, using phrases like 'Email Barry about x' - unfortunately I couldn't get this working on my UK English version of the OS.
You can set reminders to trigger when you're in a certain place, the next time you speak to a person or at a particular time of day. All of these are useful - particularly when used in conjunction with a mobile Windows device, such as a phone or tablet, which are more likely to be tracking your location or used to call someone. Cortana can also plug into the Office365's Calendar and offer users appointment reminders, information on when and where to go for meetings, travel times to work, and updates on flight times and the like for upcoming trips. The idea is that Cortana will tell you everything you need to know about your day.
The version I'm testing is a near-release version of Windows 10 Pro. Windows 7 Pro and Ultimate and Window 8.1 Pro users will be upgraded to Windows 10 Pro, while Starter and Home users will receive Windows 10 Home. To buy the OS would cost you $119 for the Home and $199 for the Pro version.
The professional version of Windows 10 has three core differences from the home version - the inclusion of BitLocker encryption, Remote Access and support for Hyper-V virtualization. BitLocker encrypts storage volumes, Remote Access allows you to log into another PC over the internet and Hyper-V allows you to create virtual machines for running other systems.
Tests were run on a Toshiba Portege laptop. The machine has an 2.1GHz Intel Core i7 4600U processor, with 8GB of memory and a 256GB SSD.
It's useful to have this overview of your day but for desktop users to get the most out of these features they need to have this information at hand when they're travelling - which means they also need a Windows phone or to run the Cortana app on the iPhone or Android handsets.
Cortana also resorted to performing a simple web search too often for my liking. When it doesn't know how to answer a query Cortana will instead open up the Edge browser showing the results of search using Bing. It can do this for disappointingly simple searches - asking Cortana 'Best restaurant nearby' gives you a list of sites that rate restaurants, rather than the required information. This is despite Cortana offering me ratings and addresses for local restaurants when I clicked on Cortana's bar close to lunchtime. Giving you information when you don't want it and not giving you the same information when you ask for it doesn't seem that smart. The information shown in Cortana's box, the national news and restaurant reviews can also feel like a bit of a ragbag of unwanted trivia. Perhaps what it shows you will become more useful over time, as Cortana learns more about you and your interests.
Unfortunately voice recognition also didn't work for me, so I had to interact with Cortana by typing.
Separating mobile from desktop users
Another advantage Windows 10 has over its predecessor is that it leaves behind the idea of being all things to all men. Rather than Windows 8's attempt to offer a single interface that straddles desktop PCs and tablets - and serves neither particularly well - Windows 10 has a distinct look for tablets and desktops. Continuum Mode allows Windows 10 to detect when a device is docked with a mouse and keyboard or being used as a tablet and to reorient its UI to suit. For instance, in Tablet Mode the Start Menu brings the large, easy to tap Live Tiles found in Windows 8 to the fore, while in desktop mode it emphasises Windows menus stacked with small icons that are no problem to click with a mouse.
"Universal" apps from the Windows Store can also adapt their interface to suit mobile and desktop devices. These universal Windows Apps share their core code but can switch their interface to be equally usable across desktops, phones, and tablets. A simple example is an app that starts in a window in desktop mode but that pushes the window fullscreen when started in Tablet Mode.
My laptop is unable to take advantage of Continuum mode. But this adaptive UI could prove to be a real draw for Microsoft as PCs shift from laptops to 2-in-1 machines that can be converted into tablets by detaching or hiding the keyboard.
The main problem Microsoft needs to address, and has been unable to do so for years, is the lack of good quality universal apps in the Windows Store. Many of the best desktop apps don't have decent counterparts in the Windows Store.
The store, which provides an easy way to download and install Window applications, is pinned to the Taskbar by default. You'll find apps to serve basic consumer needs - such as Facebook and Twitter but some apps found on rival app stores are missing, such as Instagram and WhatsApp. The store's presentation could also be cleaner. While it has less junk and misleading titles than it used to, it still labels "guides" to using apps, rather than the software itself, as "Apps". That said, there are a wealth of desktop apps that can be installed on Windows 10 and most Windows desktop applications I tried running - Spotify, GIMP, old versions of Word and Excel - seemed to work happily on Windows 10.
On the Edge
One of the biggest problems with Windows 10, at least in the near-release build I used, was the Edge web browser.
Based on a new rendering engine and jettisoning much of the legacy code gunking up Internet Explorer, Edge has been designed to be both fast and able to handle modern websites and services without breaking.
Like other major browsers, Edge handles 1080p video playback with ease and most modern web services like Google Docs, Gmail and Drive without rendering problems - perhaps a result of Microsoft's commitment to Edge supporting latest web standard technologies. However I couldn't get Google Hangouts to work in Edge.
Being able to highlight people and places on a webpage and get Cortana to overlay more information is a nice touch - adding context without leaving the page. But some of Edge's new accessibility features also proved unstable - with the reading mode, designed to strip away all but the main article from a page, failing to work on occasion.
Software and services
Windows 10 comes with various built-in apps - including email and calendar clients, a photo viewer, maps program and a movies and TV player with a built-in store and a music player that can connect to a Groove Music streaming service. The maps app integrates Bing search to add in information about places of interest nearby, while the photo app provides basic editing capabilities and support for GIFs and the RAW file format. Setting up the mail client to handle a third party email service like Gmail is simple - with the app walking you through how to link your account. Windows Media Center has been scrapped and is no longer part of Windows.
As with Windows 8, Windows 10 doesn't include support for Blu-ray or DVD playback but this can be remedied by downloading the desktop version of the free media player VLC.
When it comes to word processing, WordPad works fine for simple use. Consumers can also download mobile versions of Microsoft Office apps from the Windows Store, although the touch-oriented interface isn't suited to the desktop and you have to subscribe to Office365 to create documents. OneNote is available for making and sharing notes - although getting it to crop content from webpages - rather than just a link to the page wasn't immediately apparent to me.
Windows 10 also supports DirectX 12, the latest version of Microsoft's API used to communicate with your graphics card. This may sound pretty dull but DX12 should allow graphics cards to render 3D games while delivering better framerates than was possible in DX11-based Windows 8. I couldn't test DX12 on my laptop's Intel HD graphics, but it certainly seems to make a difference in a synthetic benchmark run by tech site Anandtech, which found it enabled a more than 16x increase in the number of draw calls per second on a Radeon 290x graphics card.
Like Windows 8, Microsoft's cloud storage offering OneDrive is integrated into Windows 10 and can be set up to automatically sync files from the service to your PC. This allows access to the same files across various PCs, phones and tablets - wherever you can access OneDrive from. However, Microsoft has changed how OneDrive works in Windows 10 - no longer displaying placeholders in File Explorer for OneDrive files not stored on the device. Although Microsoft said it made the changes to avoid confusion over offline availability, it is looking into new ways to show OneDrive files not available locally via a future update.
Security and privacy
With Windows 10 Microsoft is hoping to make users far less reliant on passwords. The Windows Hello feature allows users to access Windows using biometrics, specifically a facial, iris or fingerprint scan. The facial scan requires an infrared, depth sensing camera - such as Intel RealSense devices - so will probably become more useful as such hardware becomes standard on PCs and tablets. Unfortunately I was unable to test it as I lack access to a device with the necessary hardware.
Also chipping away at the password is a Windows 10 feature that allows users to log into the computer, sites and services using a PIN tied to the device. The PIN or Windows Hello can be used to log into any system tied to your Microsoft Account, including Windows 10 and Azure Active Directory, and can be used to access many different services - including Office365 Exchange Online, Salesforce, Citrix, Box, Concur - to name a few.
The operating system allows settings to be tweaked to improve privacy, such as turning off your camera and microphone. In practice some of these options seem to be broken - at least on my build - as the camera kept working in Google Hangouts in Internet Explorer after being disabled in settings. Wi-fi Sense, a feature that signs you into open wifi networks and allows your Outlook.com, Facebook and Skype contacts to automatically log in to your private networks, can also be disabled through the settings menu.
The amount of information Cortana collects about how you use the machine can also be tailored and the OS won't listen by default for the 'Hey Cortana' phrase.
For security, Windows 10 features Windows Defender, which provides real-time protection and scans against viruses and malware. In reviews of antivirus effectiveness, Windows Defender tends to rank in the middle of the pack and lacks the email and browsing protections offered by higher end security suites.
Not all it could be
If I have a problem with Windows 10, it's that there will be many desktop and laptop users who won't truly benefit from what it has to offer.
Some of the most interesting features in Windows 10 stem from the tailored services offered by Cortana. However, these services really need you to own a Windows phone or install the Cortana app to be truly useful. As helpful as it is to know how to get to my next appointment, I need to know when I'm en-route, not when I'm at my desktop.
The problem is I don't have a Windows phone or the yet-to-be-released Cortana iPhone app. And I'm not alone in not relying on anything Microsoft on my mobile, with far more people using using iPhone and Android handsets than Windows Phone.
The other issue is it's already simple to find the info presented by Cortana using alternate services on modern browsers and smartphones. When simply tapping the postcode in an email on my iPhone brings up turn-by-turn directions in the map app, why would I want to go to the bother of installing the Cortana app? If I want to be reminded to check something upon arrival I can create a reminder with Siri. If I used an Android handset I could use Google Now.
Microsoft is not doing anything wrong with Windows 10 and Cortana but it's not necessarily doing anything that makes me want to stop using all the software and services already available on the iPhone, and I suspect the same will be true for Android users. When the most interesting and useful part of Windows 10 are features that many people won't necessarily use because they are already using rival services, that seems to be a problem for Microsoft.
Perhaps Cortana's ability to learn about users will make its intelligent features significantly more useful than competing services over time. But at present it doesn't feel different enough to compel people to switch to Cortana.
Windows 10 has a lot of cool features but in general there's little that's not already available elsewhere. I'm not counting out Windows 10, it has several cards up its sleeve that could stand it in good stead. For one, it will continue to get better as Microsoft pumps out a steady stream of new features via regular Windows Updates. More importantly, Windows 10 promises to allow users to swap between tablet and PC and continue using the same apps without pause. Providing Microsoft can improve the quality of its Windows universal apps it could capitalise on the ongoing shift to hybrid tablet/laptop PCs.
Windows 10 is a competent OS and there's little reason not to upgrade. But what's most interesting about Windows 10 is what it could become, rather than what it is today.
Nick Heath is chief reporter for TechRepublic. He writes about the technology that IT decision makers need to know about, and the latest happenings in the European tech scene.