Windows 10 might well be viewed by those at Microsoft as make or break for the company. After their Windows 8 fiasco last year, after losing the smartphone market to iOS and Android, and after disappointing financial results and consequent layoffs, the software giant needs a major win to regain its footing.

But we don't need to feel sorry for Microsoft. The big question for UK IT directors and CIOs is: What does Windows 10 mean for the enterprise?

This latest and greatest Microsoft OS, which is designed to run on all devices, was released on July 29 this year for desktop and laptop devices. Releases for phones and other devices are imminent.

To encourage people to upgrade as soon as possible, Microsoft has offered free Windows 10 to anybody who upgrades before July 29, 2016. But before you bolt out of the starting gate, know that Windows 10 Enterprise is not included in the free offer. You'll probably need some of the features unique to the enterprise version, and you'll certainly want to use Windows Software Assurance. So if you are managing IT for a medium- or large-sized organisation, you can ignore the talk about free Windows 10.

Windows 10 is a completely new version of Windows - a version with new security features for the enterprises, lighter device management, and perpetual automatic upgrades that means no organisation will have to go through another major upgrade again. Because of the automatic upgrade process, IT directors might think of and upgrade to Windows 10 as the upgrade to end all upgrades.

Microsoft will release two or three modifications a year, and then every two or three years release a major roll-up as a steady-state release. Mindful that most enterprises won't want to get automatic upgrades to all devices - for example, anything that's mission critical shouldn't be upgraded without in-house testing - Microsoft offers the possibility of using existing management platforms to control updates.

One of the major new features of Windows 10 is the Universal App Platform (UAP), which allows developers to develop "universal apps" - apps that are written once, and deployed on all Windows 10 devices. IT directors should keep an eye on when and how fervently developers embrace the universal app concept.

Organisations that are already running Windows 8.1 may be disappointed to learn that not all Windows 8.1 features are retained in Windows 10. Microsoft has backed off their religious belief that "touch" should be the primary mechanism of user interface, no matter what device is being used. (With the agony of Windows 8 safely behind us, we can all look back and chuckle about how adamant Microsoft was about touch when Steve Balmer, the guy with the not-so-light touch, was president.)

While Windows 8.1 users might lose some of their favourite features, the upgrade path from Windows 7 to Windows 10 should be a smoother upgrade - good news for all the IT directors who decided to hold off on Windows 8.

Windows 10 is as inevitable as growing old

Sooner or later, all organisations will have to move to Windows 10. The only real alternative is Apple. Apple has certainly gained a foothold in the enterprise market thanks to the consumerisation of IT, and thanks to the company's partnership with the ultimate enterprise vendor, IBM. But Apple seems to play only lip service the enterprise market, putting most of its prodigious effort into satisfying the vastly more profitable consumer demand. As long as Apple keeps its distance with IT departments, Microsoft will maintain its dominant share in the enterprise.

Many IT directors are already planning to make the leap. Head of IT and Business Change at Reliance Mutual Insurance Society, Richard Norris says: "Our first impressions of Windows 10 are good. It performs well and it appears stable. If it passes our quality assurance process, I will look to deploy to the business before the end of the year."

According to Norris: "The issues regarding Windows 8 have been well documented, and the reviews of Windows 10 covered many of the concerns that had been previously raised. I can confirm that the user experience is much more intuitive than Windows 8 ever was. On top of that, there hasn't been much negative press so far."

As much as companies like Reliance Mutual Insurance Society are eager to make the upgrade to end all upgrades, other organisations prefer to hold off. One company that just upgraded to Windows 8.1 and is now considering the impact of a Windows 10 upgrade is SThree, whose CIO Lance Fisher says: "Previous experience with Windows tells us that it's best to wait until the next release, as Microsoft tend to fix the bugs in the second release. We'll probably upgrade when Windows 10.1 comes out."

On the other hand, Fisher says he is already a Windows 10 user at home. "It was a no brainer to upgrade at home, as it was free! But in a corporate environment, we need to test all our systems and policies, and that takes time. We are fine with Windows 8.1 for now."

IT directors who have not yet decided on a deployment date should base their decisions on two key factors. The first is the duration of your Microsoft support contract. If you are on Windows 7, you get support until January 2020; if you are on Windows 8.1, you get support until 2023.

The second factor is application support - when an application begins to support Windows 10 and when it stops supporting earlier versions of Windows. Once again, CIOs should poll their favourite ISVs to find out what their plans are concerning Windows 10.