Microsoft confirmed many new features in Windows 10, it's next major operating system upgrade, during an event on 21 January, when it also confirmed the upcoming software would be offered as a free download to devices running Windows 8.1, Windows 7, and Windows Phone 8.1.

The revelation that Windows 10 would be available as a free upgrade for Windows Phone users meant that the company planned to kill off the separate Windows Phone operating system. The news made since, considering Windows 10 is supposed to be scaleable and should work on a range of laptops, tablets, desktop computers, the Xbox One, smartphones, and wearables. But what about Lumia devices?

Although Microsoft didn't mention Lumia at all during its latest Windows 10 press event, it has just published new information that confirms whether Lumia devices will benefit from and be upgraded to Windows 10.

While the details are vague, the company has painted a clearer picture of what we can expect.

READ: Windows 10 will be free, spells the death of Windows Phone

First of all...Microsoft isn't the best at upgrading Windows Phones.

The company left Windows Phone 7 users in the lurch with Windows Phone 8, for instance, and it allowed some carriers to delay Windows Phone 8.1 upgrades for certain phones. But many of those complications were due to Windows Phone 8 using a new kernel that was incompatible with previous versions. Plus, the company can't really control carriers.

In the case of Windows 10, it appears Microsoft made a lofty promise, and it's now slightly backpedaling. In November, for instance, the official Lumia Twitter account publicly tweeted the following while responding to a comment: "There will be Windows 10 upgrades for all Lumia Windows Phone 8 devices :) And we will release new Windows 10 models in the future!"

The news excited many, but unfortunately, it seems like Microsoft has changed its mind.

That's not immediately clear.

Microsoft has confirmed the following information: "Like any upgrade to a new platform, not every phone will upgrade or support all possible Windows 10 features, and certain features and experiences will require more advanced future hardware."

The company also claimed it wants "the majority of the Lumia phones running Windows Phone 8 and 8.1 to join the Windows ecosystem", but it wouldn't provide any specific details. In other words: you must wait to find out if your Lumia will be upgraded.

We'll keep updating this article as we learn more.

Update 1: Joe Belfiore, the corporate vice president of the Operating Systems Group at Microsoft, has confirmed via Twitter on 9 February that Windows 10 would be available for Windows Phone devices with 512MB of RAM.

Microsoft’s most popular Windows Phone device is the Lumia 520 with 512MB of RAM. Other Lumia devices with 512MB of RAM include the Lumia 630, Lumia 625, and Lumia 530. Belfiore said Microsoft wants to make Windows 10 available for all 512MB of RAM Windows Phone devices - but features will most likely vary.

Belfiore also confirmed that a subset of phones would receive the initial Windows 10 for phones preview build when it launches for Windows Insiders, meaning it'll be limited to select devices. Windows Central claimed Microsoft is internally using the HTC One (M8) for Windows, Lumia 1020, and Lumia 1520 to test Windows 10.

The tech blog also predicted that the initial batch of phones eligible for the Windows 10 preview would likely be newer and high-end devices like the Lumia 830 and Lumia 930. Microsoft is expected to release the preview build of Windows 10 for phones in February, but it first has to complete internal testing before seeding to testers.

Microsoft has said that Windows 10 was designed with Lumia phones in mind.

"For example, with the suite of in-box apps on Lumia, you have the ease of using Mail and Calendar on your phone as you would on your PC", the company wrote in a blog post published on 22 January. "You can easily work on PowerPoint presentations, edit Word documents and appreciate other rich functionality in Office, while you are on the go."

Microsoft gave another specific example regarding its universal Maps app, highlighting that whenever you use the new app on your Windows PC to search for a place, such as a restaurant, your search will further appear in the Maps app on your Lumia phone, along with helpful information like driving directions, Yelp reviews, and the ability to reserve a table.

Apart from access to the above-mentioned universal apps as well as a full-featured version of Microsoft Office, other Windows 10 features for smartphones include a floating keyboard for one-handed use, universal speech-to-text, deep Skype integration in the messaging app, an expanded list of Quick Settings options, and actionable notifications.

Microsoft will release the latest build for Windows Insiders running the Windows 10 Technical Preview on PCs sometime within the next few weeks, though a release of the first technical preview for phones isn't expected until February.

Both the PC and smartphone versions should launch for the general public later this year.