10 things you need to know about Windows 10's release

Microsoft's uber-hyped new OS is here: what does it do, when can you get it and how much will it cost you? (Spoiler: you'll likely get it for free)

Each new Windows launch is typically accompanied by plenty of hype and nervous wondering, but this time is a little different.

See, Microsoft went an unexpected route with Windows 10, opening up pre-release access to anyone and everyone – some 5 million people took part, the company says. Those early adopters get dibs on the first downloads of the final launch version tomorrow, so the rest of you may be waiting an extra few hours (or even a day or so) to get your hands on it.

But that different approach means that some of us have been using an ever-improving version of Windows 10 for months now, so we know all about its myriad tweaks and additions. We even already know that it's really great, and a definite improvement in nearly every way from Windows 8. We won't give a final verdict until the release build is out there, but we've been thoroughly impressed so far.

If you haven't been testing the early builds or following every last detail, you might not know what to expect this week – like who gets it for free and which new features are headline perks. Worry not: here are the 10 things you need to know for this week's Windows 10 launch.

1. Wait, when?

Windows 10 officially launches on Wednesday, 29th July – but this isn't a traditional Windows launch. You won't be able to grab a box with a DVD inside on day one, or even buy a new Windows 10 PC preloaded with the operating system right out of the gate.

Instead, it's upgrades that take center stage from the start. The millions of people who used pre-release versions will get the first proper build via Windows Update, and then the surely millions more who "reserved" a copy through Windows 7 or 8 should start seeing it pop up very soon thereafter. Microsoft is rolling it out in waves to avoid potential issues, but there's a lot of anticipation around the release – surely, the wait won't be too long, but maybe you shouldn't assume you'll have it on the 29th.

2. How much?

If you have a legit copy of Windows 7 or 8.1, your download of Windows 10 will be totally free. On the house. Really! Microsoft has taken a cue from Apple in this regard, although the handout doesn't last forever: after the first year of free availability, Windows 10 will have a price tag for late updaters, plus anyone coming from Windows XP or earlier on day one will need to pay for the upgrade. It starts at US$120 (nearly £80) for the Home edition.

Note that anyone running a Windows RT tablet such as the regular Surface or Surface 2 won't be able to upgrade to Windows 10. Sorry, folks. Luckily, Microsoft has an RT update due out this September that should bring some enhancements, although we don't know what's coming.

3. How to upgrade

If you're running Windows 7 or 8.1, you'll be able to do a direct upgrade from within the OS – so you can keep all of your existing files and apps, and essentially just download an update. It should be just like what you see above, only without "Technical Preview" listed. Anyone using Windows XP or older that can actually run Windows 10 on their box will have to do a full install, meanwhile, which will be a bit more of an undertaking.

We'll have a full install guide up shortly, but however you're tackling the upgrade, be sure to back up your files beforehand. Even a seemingly easy upgrade can go perilously wrong, especially right at launch.

4. It's a Start

For many, the most noticeable upgrade in Windows 10 will be the return and modernization of the Start button. Windows 8 might have been eye-catching, but the move away from a typical desktop design alienated a lot of users. Windows 10 makes strides to fix that problem.

But it still acts like a bridge between the perks of Windows 7 and 8, as the new Start menu houses those big, bright tiles from the latter amidst the traditional list design of the former. And now with Cortana and other functionality also integrated, the Start menu is not just a nostalgic return, but also seriously useful as well.

5. Hey, Cortana

Did we say Cortana? We sure did. The Windows Phone personal assistant makes the leap to desktops in Windows 10, and she's integrated in a couple of ways. As we mentioned, she's there in the Start menu, so you can click the Windows button or start typing into the search bar to activate her brainy skills. You can also just speak into your PC's microphone.

And that's not all. Cortana is also built into Edge, Microsoft's new web browser, to help you get extra details in a hurry while surfing around. Because Cortana is a learning personal assistant, she'll get to know your tendencies and cross-reference events and contacts from your various social accounts and interactions.