As Microsoft prepares to launch Windows 8 on a new generation of high-powered tablets, initial reviews of the new operating system underscore the challenges the company faces with the radical redesign of its flagship product.
The world's largest software company says millions of people are already using a downloaded pre-release version of Windows 8 on PCs, laptops and touch-devices ahead of its full introduction this autumn.
At a media event in Los Angeles today, the company is expected to discuss its plans to take on Apple's all-conquering iPad this holiday shopping season.
So far, most reviewers have praised the look and feel of the touch-friendly "Metro" style of Windows 8, which is based on colorful squares, or "tiles," that depict applications such as email, and update in real time.
But they have also stressed how difficult it will be for users to move away from what they know and trust.
"It's a bit of a struggle for people who are deliberately oriented on a PC, that are used to a mouse feel," said former Microsoft strategist Al Hilwa.
Now an analyst at tech research firm IDC, Hilwa has been trying out the latest demo release for two weeks. "Without a touchscreen, I struggled with a mouse to do certain things," he said.
The new Metro interface only runs programs written for it, so users have to switch back to the traditional desktop to do certain tasks, like listening to music on Apple's iTunes.
"The thing that really infuriates me is that it seems like Metro apps, and apps running in the normal desktop don't have any knowledge of each other, " said Forrester Research analyst David Johnson. "There's no easy way to navigate between them, and I'm not quite sure why that is."
The latest test version is not yet finished software. And outside of a few industry testers, no one has tried out Windows 8 on a tablet powered by ultra-efficient ARM Holdings chips, which is the closest Microsoft will come to challenging the iPad.
Microsoft is expected to say more about that on Monday, and there is talk that it might introduce a tablet under its own brand name. The company declined to comment on the reaction to the new system and its plans for the Monday event.
Nevertheless, Microsoft has not persuaded some of its most loyal users just yet.
"Right now, I'm not sold," said analyst Michael Cherry of Directions on Microsoft, an independent research firm that focuses on the tech giant.
Cherry said he had persevered with Windows 8 for a few days, but had problems setting up email on his test machine. "I can't rely on it as a production tool," he said. "I can't switch over yet. At this point, I should be able to leave Windows 7 behind."
A former Microsoft program manager, Cherry worries that the initial complexity of the new system will prevent it from being an instant hit, like its predecessor, Windows 7.
"If a guy who has used Windows since Windows 1.0 can't figure it out, then I'm going to guess there are other people out there who aren't going to figure it out," he said. "We won't see line-ups at Best Buy at midnight. I'd love to see that, but it's just not there."
