Analysts brands operating system as confusing.

Analysts have criticized Microsoft's latest operating system Windows 8 by calling it confusing and for playing its part in slow PC growth.

In a research note from analyst Chris Whitmore, the first reason Deutsche Bank attributed for decreasing its PC estimates this quarter was a "lackluster initial uptake of Windows 8." In addition to referring to the impact of "macro weakness" and the "fiscal cliff", he continues:

"As in past cycles we expect the introduction of a new Microsoft OS to spur an increase in PC demand. However...we believe Win8 will have a more muted impact than prior cycles for a several reasons: 1) Win8 reviews are mixed due to a confusing UI; 2) there is a lack of Enterprise interest in Window 8; 3) tablet form factor complicates positioning (Win8 vs. Windows RT), 4) continued substitution of PCs by iPads/tablets 4)."

Usability expert Jakob Nielsen said Windows 8's downfall is its "confusing UI", which is other known as the user interface. Topeka Capital Markets analyst Brian White added that Windows 8 orders have been weak. "Much lower than PC makers originally expected a few months ago."

Paul Thurrott, a technology blogger and Microsoft insider, had recently said that Windows 8 PC sales have fallen 'well below' Microsoft's projections.

Computerworld, who has tracked usage patterns of Windows 8 in the months prior to its launch and during its release, found that the OS "is being run by less than a fifth as many people as ran Windows 7 in the same months before its debut."

According to a survey, more than half of consumers haven't heard of Windows 8, with those who are aware of the operating system simply not interested in the platform.

With a $1.5 billion investment in marketing for Windows 8, four million units were sold in its first three days of availability.