The next Windows operating system, now officially known as Windows 10, may not arrive until Fall of 2015. The announcement came from CEO Kevin Turner, as reported by Tom's Hardware.

According to the outlet, Turner revealed that Microsoft is set to discuss more of the upcoming OS's end-user experience in Spring. This will be followed by a developer preview some time in early Summer. A final, retail-version launch is expected between late Summer and early Fall.

ZDNet cited Turner's statement on Dec. 4's Credit Suisse Technology Conference, "And then by next late summer and early fall we'll be able to bring out this particular OS. That's the current plan of record."

Unnamed sources told the outlet that Microsoft is unveiling the Windows 10 Technology Preview and Windows 10 mobile SKU in late January. The latter is expected to run among Windows Phones, ARM tablets and Intel tablets. Meanwhile, Microsoft's Windows developer event "Build 2015" is set in April's last week.

Windows 10 has garnered much anticipation from the previous months, when Microsoft executive Terry Myerson told USA Today, "When you see the product in its fullness, I think you will agree with us that it is a more appropriate name." He has hinted since then that the OS might see its launch "later in 2015."

The OS was also coded "Windows Threshold" from the time it was speculated to be Windows 9. Apparently, Microsoft has taken everybody by surprise with its numerical jump from Windows 8.1.

In the meantime, TechSpot reported that Cortana, Microsoft's virtual assistant , has appeared in a pre-released version of Windows 10. The source cited WinBeta as able to get this early access, predicting that the feature will look "more polished" once the OS' final version rolls out.

Cortana is Microsoft's version of Apple's Siri and Google Now. In WinBeta's video, she (Cortana personified) was able to execute the following functions:

1. Skype Calling - the user asked Cortana to call someone via the service and she automatically responded. The Skype window opened -- and if the user has signed in, she dials the receiver's channel without further ado.

2. Near-Calendar Productivity - the user asked Cortana, "What's on my schedule today?" After a few seconds, she responded "Okay. I can check your calendar. Here's what you have today." If the user had any appointments, she displays them right on the prompt.

The user continued, "Put something on my calendar."

Cortana asked, "Sure. When's your event?"

"5 p.m. today," the user answered.

"What should I call it?" Cortana clarified.

When the user told "swimming," Cortana broke out. This revealed that the current system didn't really connect with the calendar yet.

3. Reminder - the user asked Cortana to remind him of an activity, and the system appeared to execute this function quite successfully -- except for the erratic transcription of "work" to "luck."

4. Alarm Setting - Cortana was able to set the user's requested alarm at 6:00 a.m.

5. Note-Taking - Cortana transcribed another reminder of the user, this time in the form of a note.

This build of the system is also capable of playing music, locating nearby establishments and checking weather status.

The Windows 10 beta may be downloaded here, wrote Ars Technica.

Watch WinBeta's preview of Cortana in Windows 10 below.