Microsoft looks ready to kill off Windows RT, its version of Windows devised for chips based on ARM's architecture, judging by remarks by senior executive Julie Larson-Green.

Larson-Green, who is executive vice-president of Devices and Studios at Microsoft, said that the aim of Windows RT was "our first go at creating that more closed, turnkey experience [that Apple has on the iPad]…" but that Microsoft now has three mobile operating systems: "We have the Windows Phone OS. We have Windows RT and we have full Windows. We're not going to have three."

Her comments, made at a UBS seminar, appear to confirm the growing suspicions that Windows RT has been a failure both with OEMs PC makers and developers, who have all but abandoned it. Only Microsoft and Nokia's handset division, which is being acquired by Microsoft, make any RT devices. Microsoft had to write down $900m at the end of the June quarter on unsold Surface RT devices.

Richard Windsor, who runs the Radio Free Mobile consultancy, commented: "I have long suspected which is that Windows RT will be killed off sooner rather than later. Always one to treat hot potatoes delicately, Microsoft has not explicitly said that RT will be terminated but has made it very clear that there will not be three operating systems. Windows RT is an orphan child that sits between Windows 8 and Windows Phone and is neither fish nor fowl. Hence the devices that are based on it are underpowered with hideously limited functionality on the desktop making them inferior to both Android and iOS tablets."

"I suspect that there will be no Surface 3 and no successor to the Nokia 2520 [an 8in tablet running Windows RT]. Furthermore I am confident that RT will be quietly put to sleep during 2014."

A focus by Microsoft on Windows Phone and "full-fat" Windows - the latter able to run all the legacy applications from the past two decades - would simplify the company's OS strategy.

Larson-Green explained the original aim of Windows RT: "Windows on ARM, or Windows RT, was our first go at creating that more closed, turnkey experience [like the iPad], where it doesn't have all the flexibility of Windows, but it has the power of Office and then all the new style applications. So you could give it to your kid and he's not going to load it up with a bunch of toolbars accidentally out of Internet Explorer and then come to you later and say, why am I getting all these pop-ups. It just isn't capable of doing that by design.

"So the goal was to deliver two kinds of experiences into the market, the full power of your Windows PC [on the Surface Pro], and the simplicity of a tablet experience that can also be productive. That was the goal. Maybe not enough. I think we didn't explain that super-well. I think we didn't differentiate the devices well enough. They looked similar. Using them is similar. It just didn't do everything that you expected Windows to do. So there's been a lot of talk about it should have been a rebranding. We should not have called it Windows."

Microsoft announced Windows RT at the Consumer Electronics Show in January 2011, and launched it in October 2012 at the same time as Windows 8, having planned it to take advantage of what it thought would be a new wave of personal computers built on ARM chips rather than Intel. ARM chips generally have the advantage of low power requirements, leading to their use in smartphones and tablets.

But the market never materialised, and buyers mostly shunned the Surface RT because of a relative lack of apps, and confusion over why popular programs such as Apple's iTunes and Google Chrome were not available for it.

Manufacturers abandoned it rapidly as they saw that there was no market for PCs based on Windows RT. Samsung decided not to sell its RT-based Ativ line in the US before January, citing weak demand and no clear idea of the "value proposition."

In July, Asus's chairman Jonny Shih said that "the result [of building RT devices] is not very promising."

In September, a Lenovo executive said there was "no longer a need" for Windows RT given the improvements made by Intel in power consumption in its Haswell chip.

Dell was the last besides Microsoft to leave the RT space, dropping its XPS 10 in September.

Meanwhile Windows Phone has been scaled up to larger and larger screens, such as the 6in 1520, and smaller 8in tablets with Intel architecture have begun to go on sale - leaving Windows RT with no obvious niche.

Nokia's release of the 2520 has surprised some - though its announcement after the deal with Microsoft to buy the handset business points to an attempt to support its buyer's aims.

But Windsor said that it would have been made in small quantities: "I suspect that volume commitments to the Surface 2 [an RT tablet] and the Nokia 2520 are almost non-existent. Hence I am pretty certain that there will be no repeat of the huge write-off endured by Microsoft for either company."

He said that the decision to sideline RT is "excellent news" as "Microsoft is being more pragmatic in its approach to strategies that don't work. If Microsoft can apply this pragmatism to the rest of the company and to its choice of CEO, we might just have a phoenix rather than a turkey."

Larson-Green also acknowledged that the reorganisation of Microsoft by outgoing chief executive Steve Ballmer was part of a long-running discussion within the company. "When I ran the Windows organization my job was to really get other groups inside of Microsoft to bet on the platform and we had Bing build apps for us. We had Xbox team build music and video that became the default music and video experience for Windows. We had Office building OneNote on our new experience. And so it's not completely foreign to us to work cross group. But, the incentives in how you worked, we had different ship cycles, we had different P&L goals. There was no mal-intent, it was just we were busy with our own things. Now we're busy with one thing. We're busy with bringing together the experience for our customers at a Microsoft level."

Asked how Microsoft would compete in tablets, Larson-Green said: "with Apple there was an inflection point with tablets, or with phones, with touch… There will be another inflection point and it's going to come from the hardware input model. So that's why you've seen us doing things with Kinect, with gesture. You see us doing things with voice. There's one coming."

Asked how Windows on tablets could compete with Apple's app ecosystem, she said: "So you enable a new kind of app. So [Apple] were very successful in creating a curated set of applications that took what most people were trying to do on the web and made it valuable to do it on the device and created a model for them to get paid and all those things. There will be another one of those coming is my belief. I think you already start to see some of it. I think connecting apps to each other, because so many things are special purpose, you'll start to see new ways for apps to integrate across. I think there's a lot that's going to come from the web in smart information about you and your location."