Microsoft plans to release a preview version of its Windows 8 update, code-named Windows Blue, at the end of June, according to Julie Larson-Green, a corporate vice president in charge of the operating system's development.

Larson-Green didn't say what changes Windows Blue will feature, but conceded that Microsoft has discussed user complaints about the removal of the Start menu on Windows 8 and that it might be useful to restore it.

"We're principled in the direction we're heading but we're not going to be stubborn," she said.

The Windows Blue public preview will be released at Microsoft's Build developer conference, slated for June 26-28 in San Francisco, the company later confirmed.

Earlier in the day, the other Windows chief, Tami Reller, announced that Windows Blue would be released before the end of the year.

Reller, Windows CMO and CFO, didn't say what will be new in Windows Blue, but she said that the OS update would be "an opportunity for us to respond to the customer feedback that we've been closely listening to."

Windows 8 has been controversial from the beginning. It sports a radically redesigned interface based on tile icons intended to make the OS optimised for touchscreen devices like tablets. However, it has not been an unqualified success, and the lack of uptake by users has been blamed in part for the dismal performance of the PC market overall.

Larson-Green also acknowledged that Microsoft has "some work to do" to better articulate the benefits of its Surface RT tablet, which apparently hasn't sold as well as expected and which runs Windows RT, a Windows 8 version for devices based on ARM chips.

Reller said that Windows 8 has topped 100 million licences sold after about six months on the market, but Gartner analyst Michael Silver said the statistic shouldn't factor into any decision about Windows 8 in enterprises.

"IT directors and CIOs shouldn't really take anything away from these momentum numbers," he said. "They need to consider what they have and what they need and make decisions based on that."

That means organisations with a large contingent of Windows XP PCs need to prioritise upgrading from it because support for that 12-year-old OS is ending in April of next year, he said.

"If they are in the midst of deploying Windows 7, they need to keep going," Silver said.

Organisations looking to deploy hybrid devices, such as laptops with detachable keyboards that can double as tablets, should consider Windows 8, as long as "a big business benefit" can be obtained, he said.

"For organisations that are uncertain about the business benefit for Windows 8, waiting for the next release makes sense," Silver said.

IDC analyst Al Gillen expressed frustration at the lack of specifics about what will be new or changed in Windows Blue. Considering the update will be out this year, Gillen speculates that the limited information indicates it will not contain "dramatic, wholesale changes."

The focus will probably be on "look and feel" modifications, and not so much on disruptive, underlying technical alterations, he said.

He thinks it's unlikely Microsoft will retreat to a Windows 7-style design, but even without doing that he said the company could make the user experience smoother between the Windows 8 "modern" interface and its more traditional interface, which users can toggle between in the current version of the OS. The Windows 7-like interface is used to run "legacy" Windows 7 applications, while the tile-based "modern" interface is for new applications.

Windows 8 is too aggressive in shifting users back to the "modern" UI, which is an annoyance for people who spend most of their time using Windows 7 applications, he said. "Microsoft needs a smoother transition story across the two products," he said.

He doesn't anticipate significant changes to the application development APIs (application programming interfaces), so developers likely won't have to make changes to their applications.

Gillen would also like Microsoft to be more specific about what customer feedback it is paying more attention to. "We're in the dark there," he said.

Microsoft appears to be leaving the door open to certain changes without locking itself into specific deliverables, Gillen said.

Reller also said in her blog post that the number of certified devices for Windows 8 and Window RT has grown to 2,400, a statistic that is a double-edged sword, according to Forrester Research analyst David Johnson. It's good to offer such a variety of devices to consumers and enterprises, but the volume of options can complicate the purchasing process, he said.

Reller also said that the number of Windows 8 apps in the Windows Store has increased six-fold since its launch, and that there have been more than 250 million downloads.

While the numbers paint a positive picture of app growth, a more important element is the maturity and quality of those applications, which will only improve as developers gain experience and become more comfortable with the new OS, Johnson said.