Microsoft co-founder Paul Allen today called Windows 8 "puzzling" and "confusing initially," but assured users that they would eventually learn to like the new OS.

Allen, who co-founded Microsoft with Bill Gates in 1975, left the company in 1983 after being diagnosed with Hodgkin's disease. He is best known in the US as the owner of the Seattle Seahawks American football team and the Portland Trailblazers basketball team, and as a part-owner of the MLS' Seattle Sounders football club (or soccer as it's known over there).

In a post to his personal blog Tuesday -- strangely titled in the third person as, "Paul's take on Windows 8," Allen said he has been running Windows 8 Release Preview -- the public sneak peak Microsoft shipped May 31 -- on both a traditional desktop as well as on a Samsung 700T tablet. The latter, designed for Windows 7, not its successor, has been handed out or loaned in quantities by Microsoft to developers, analysts and members of the press in an effort to convince them to create software, or try out the touch-first features of Windows 8.

"I did encounter some puzzling aspects of Windows 8," Allen wrote, and said the dual, and dueling user interfaces (UIs), were confusing.

"The bimodal user experience can introduce confusion, especially when two versions of the same application -- such as Internet Explorer -- can be opened and run simultaneously," Allen said.

A tale of two interfaces

Windows 8 has come under fire from some quarters for a variety of reasons, but the one most cited has been the double-UI approach, one dubbed "Modern" or "Windows 8 style" (formerly "Metro") that features a flattened, minimalist look and responds best to touch and gestures, and the other, called "Classic" by a few, that resembles a tweaked Windows 7 desktop sans a Start button and Start menu.

Allen also repeated criticisms of Windows 8 that have been long-expressed by users, Microsoft watchers and analysts.

"Strangely, there is no way to set the desktop as your default view (there should be)," Allen wrote. "This is one of the single biggest changes in Windows 8: the lack of the familiar Start menu."

He also took Windows 8 to task for not helping users learn the new Windows 8 style UI and for hiding the shutdown command, points others have made. "Personally, I think it would have been nice to provide some sort of a visual cue indicating that commands are available, and how to invoke them," he said.

"I found myself wishing that a Power tile was available on the Start screen to make these commands more accessible," Allen said.

Microsoft does offer a very animated tutorial during setup that demonstrates how to access the Charms menu, but that's the extent of its opening-round assistance.

In fact, Allen dedicated an entire section of this blog to the topic of "Puzzling aspects of the Windows 8 UI" that detailed everything from multiple-monitor desktop and notebook setups to the lack of a clock on the Start screen.

He concluded, however, that even with its out-of-the-box quirks, Windows 8 would be manageable by users and that Microsoft would address them in the next release. "While these changes may prove confusing initially, after a short period of discovery most of these changes should quickly become familiar," said Allen. And like most other long-time Windows users, he applauded Microsoft for assembling an OS suitable for tablets, the hottest category of computer-like devices.

"Touch seems a natural progression in the evolution of operating systems, and I'm confident that Windows 8 offers the best of legacy Windows features with an eye toward a very promising future," Allen wrote.