Microsoft has set a release date for Windows 10 to arrive in the summer.

The software maker announced Monday that it will begin offering its newest software to power PCs and tablets as a free upgrade on July 29. Windows 10 Mobile, the company's companion software designed to power smartphones, is expected to arrive later this year. Windows 10 will be free for users who have bought a computer in the past six years or so, powered by Windows 7 or later, or tablets running Windows 8.1.

Users running Windows 7 or 8.1 with the latest updates can reserve the upgrade starting today. Check out CNET's guide for more details.

Windows 10 marks the next iteration of the one of the world's most ubiquitous pieces of software. Microsoft's operating system powers a majority of personal computers and acts as the backbone of many of the world's businesses. Despite its dominance, Microsoft critics see the company and its products as a tech titan in decline, as mobile phones and competing, cheaper software have chipped away at Windows. The company's goal with Windows 10 is both to repair the damage done by the ill-received Windows 8 and to convince consumers that upgrading is worth the time and effort.

Rumors originally swirled around a July release date for Windows 10 back in April when Lisa Su, head of chipmaker AMD, discussed the timeline on a conference call. Microsoft has mostly remained mum, coyly avoiding discussion of a launch date even during its developer conference in April. Some industry watchers became concerned the software may not be ready in time.

Microsoft has not disclosed when computer makers will begin selling PCs pre-loaded with Windows 10 or when retailers will sell individual licenses in the event you are not eligible for a free upgrade or wish to build your own computers. However, a leak from online retailer Newegg on Saturday indicated that PC makers would receive the software August 31. Newegg also leaked screenshots revealing that the software sold on its own would cost hardware makers $109, while the Professional version will run $149, according to the listings, which were first spotted by ZDNet.

Through its Windows Insider program, which lets eager users sign up to receive developer versions of the software-in-progress, Microsoft has been more transparent with Windows 10 than previous releases. Since its unveiling in September, those early users have watched the software's evolution firsthand. Some of the key changes Microsoft has made include a revamped Start button and the removal the unpopular tablet-focused interface of Windows 8. There's also a new browser, Edge, to replace the decades-old Internet Explorer, as well as a more robust version of Cortana, Microsoft's voice-enabled digital software assistant.

The most important aspect of Windows 10, however, is the company's philosophy powering it: one Windows to rule them all.

Microsoft remains the world's largest software maker, with Windows running on more than 90 percent of the world's computers, according to NetMarketShare. But the company had a late start on smartphones and has struggled to keep its software relevant while developers focused on Apple's iOS mobile operating system, Google's Android and the Web at large. PCs sales have also been on a steady decline.

With Windows 10, Microsoft is making a big gamble that its Windows software can power a web of devices, attracting customers to own computers, tablets and smartphones all powered by one company's software. It's a gamble that's worked for Apple, whose iPhones, iPads and Macs are well regarded for working well with one another.

Microsoft executives, including CEO Satya Nadella, have stressed the importance of thinking of Windows and Microsoft software as services, not products we buy. The company has already begun applying this model to its Office software suite, which includes programs like Word, Excel and Outlook. Microsoft now available offers it as subscription service, called Office 365, instead of selling individual disks to customers at a one-time flat rate.

The company has not yet said if there will ever be a Windows 11, or a version of Windows we consumers will pay for like past releases. Users who update to Windows 10 will get "new features and benefits for a long, long time," said Joe Belfiore, Microsoft's vice president of operating systems, said at Build earlier this month.

Though it still makes most of its money selling its traditional software to businesses, Microsoft's fastest-growing business division now is its cloud services group, which is on track to make $6.3 billion in sales this year. Nadella, who oversaw Microsoft's cloud business before assuming the role of chief executive in February 2014, hopes to see annual sales there grow to $20 billion over the next three years.

By 2018, Microsoft hopes to have more than 1 billion devices running Windows 10. That's ambitious, particularly considering Microsoft's previous release, Windows 8 which arrived in 2012, powers less than 15 percent of the world's computers.