Jessica Dolcourt/CNET

Five years ago, Microsoft tried to radically transform the way a Windows computer would work.

At the core of this change was the embrace of chips, made by companies including Qualcomm, that typically powered smartphones and tablets. It marked a dramatic deviation from the use of the x86 chips from Intel and AMD that traditionally served as the brains of a Windows PC.

At the same time, Windows RT, a lightweight version of Windows 8, would enable thinner and lighter PCs and tablets. It would help Microsoft and its partners like HP and Dell better compete against Apple's iPad. And it would get people excited about PCs again.

None of that really happened, and Windows RT bombed. Less than three years after it hit the market, the software ceased to exist.

But Microsoft, along with Qualcomm, HP and others, is now back for a second try. Together, they've created "always connected PCs" that are powered by Qualcomm Snapdragon chips.

The renewed effort comes as you spend more and more time on your smartphone and as the market for PCs continues to shrink. The answer? Turn your next PC into something more akin to your phone. For Qualcomm, PCs mark a potential new business at a time when Intel has created a 4G LTE radio good enough to power Apple's iPhone. Microsoft and PC makers hope the longer-lasting computers get you to give their products a second look.

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The first two devices, 2-in-1 laptops from HP and Asus, promise more than 20 hours of battery life, always-on connectivity and the ability to instantly wake. And importantly, they run full Windows and can use ordinary Windows apps.

"You get everything you have come to expect out of Windows plus all of these new things," Cristiano Amon, executive vice president in charge of Qualcomm's chip business, said in an interview Tuesday at the company's tech conference on the Hawaiian island of Maui. "It completely changes the value proposition from what the original Windows RT was."

If Microsoft, Qualcomm and their PC partners want these new devices to succeed, they'd better hope that's true.

Windows RT's doomed existence

It's almost impossible today to introduce PCs that run on mobile chips without mentioning -- or at least thinking of -- Windows RT.

That software hit the market in late 2012 as a lightweight alternative to Windows 8. It struggled immediately, in part because traditional Windows programs, like Outlook, wouldn't run on it, and in part because it confused consumers, who couldn't understand the differences between RT and full-blown Windows 8.

Microsoft also tightly controlled the development process for Windows RT devices, limiting the number of companies with which chipmakers could work, saying that would make for better devices. It was trying to emulate Apple's model of controlling both the software and hardware experience.

But that meant few products, outside Microsoft's own Surface, ever hit the market with the software. Microsoft itself overestimated how many Surface RT units it could sell and had to write down the value of the tablets. One by one, other PC vendors and chipmakers ditched Windows RT before Microsoft finally killed the last tablet running the software in early 2015.

"When you make something that has a limited experience, it always has to be counteracted by some sort of other big benefit," Moor Insights & Strategy analyst Pat Moorhead said. Windows RT devices weren't thinner or lighter than x86-powered rivals. At the same time, they were less powerful and ran a limited number of applications.

"In a way, Windows RT was the worst of both worlds," Moorhead said.

Microsoft and Qualcomm, the world's biggest wireless chipmaker, weren't ready to give up completely, though. The two announced plans a year ago to make Windows 10 run on Qualcomm's Snapdragon processor, the same chip that powers Samsung's Galaxy S8 and the Google Pixel 2.

This time around, they took steps avoid to the problems of the past.

"We all have battle scars from RT," Miguel Nunes, product manager for Qualcomm's Windows on Snapdragon operations, said in an interview. "None of us could afford another Windows RT."

Second time around

When Microsoft and Qualcomm set out to make Windows 10 run on Snapdragon chips, they knew they couldn't risk a flop. The devices had to be more like smartphones, with more compact designs, better battery life, wireless connectivity and always-on capabilities. And importantly, they couldn't run a stripped-down version of Windows.

"There was a decision made by Microsoft and Qualcomm that there is no second-class system of Windows," Amon said. "It is just Windows. Period."

HP, Asus and Lenovo jumped on board and started building devices that sport Qualcomm's Snapdragon 835 processor and its X16 LTE modem. In the case of HP, its Envy x2 features a 12.3-inch display and will last up to 20 hours on a single charge and up to about 30 days in "modern standby mode." The device will have up to 8 gigabytes of RAM and up to 256GB of storage when it launches in the spring. Pricing isn't yet available.

The Asus NovaGo has a 13.3-inch LED-backlit full HD display, and it can run 22 hours of video or stay on standby for 30 days. It will start at $599 for 4 gigabytes of RAM and 64GB of storage. The $799 model will get 8GB of RAM and 256GB of storage.

Lenovo will unveil its device at CES in January.

"This is a full PC, and it's fundamentally transformed the way I work," Terry Meyerson, executive vice president of Microsoft's Windows and devices group, said Tuesday at Qualcomm's tech summit. The PC he's been using, he said, needs to be charged only once a week, wakes up immediately and always has a connection when he needs it.

What's different this time around goes beyond the devices themselves, said Amon. Mobile processors have become more powerful, and people have gotten more comfortable with cloud computing, accessing data over the Internet instead of storing it on the device itself. Think Google Docs or photos stored in iCloud.

"Expectations are now being defined" by smartphones, Amon said. "Those are significant changes from where we started."

Trading off

The new Snapdragon-powered PCs may appeal to some buyers, but they also have some drawbacks. They're mainly aimed at people who want to search the web, access social media, check email or consume content such as videos. They won't work well for photo editing or intensive gaming.

Qualcomm has been pushing for more and more devices to come with built-in wireless connections. No more waiting for Wi-Fi when your tablet has LTE. But that means another cellular plan -- something consumers haven't exactly been clamoring for.

In a Creative Strategies study, about half of the iPad users surveyed opted for the pricier LTE version of Apple's tablet. Only 49 percent of those people actually activated LTE on the tablet. (For those of you who hate math, that means only about a quarter of people use LTE on their tablets.)

For those who did set up LTE on their iPads, it was "mostly for peace of mind," Creative Strategies analyst Carolina Milanesi said.

It's common for cellphones to come equipped with mobile hotspots that let you share Wi-Fi with your other devices. That makes having a modem inside your computer or tablet less important. If having connectivity in a PC becomes vital, it's likely Intel will put its own 4G LTE chips in computers.

And while Microsoft and Qualcomm tout the devices' ability to use "full Windows," that comes with some caveats.

The version of Windows running on the devices is 10 S, which is a more locked-down experience. The software only runs applications downloaded from Microsoft's Windows Store. And though the Snapdragon-powered devices can run traditional Windows apps, it's through a process called emulation, which can make the machines lag in some instances.

The pitch from Microsoft, Qualcomm and the PC makers is that Windows 10 S is more secure. All apps in the Windows Store have been approved by Microsoft, making malware and other issues less likely.

Now it will be up to consumers to decide whether a smartphone-esque PC is what they want.

"The question is if [these devices] are better enough to justify the potential concerns," Technalysis Research analyst Bob O'Donnell said. "The tradeoffs are much more interesting this time than with RT."

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