Microsoft has now revealed the minimum hardware requirements for tablet computers to run Windows 8, another sign the company wants to extend its operating system (OS) to a wider range of devices.

Windows 8 is the first Windows operating system designed to work on everything from desktop PCs to tablets.

Aside from the classic desktop design, it boasts a user interface called 'Metro' that's intended for small touch-screens. Some critics fear Windows 8 might be so focused on tablet compatibility that it offers very little improvement to users of notebook and desktop PCs.

Windows 8 Tablet: Guidelines Overview

Microsoft's approach to tablet manufacturing standards is similar to the rules it lays down for smartphone makers.

For example: Microsoft is less restrictive than Apple, which makes its own devices and refuses to license its operating system to other manufacturers. Thus, Apple is in complete control over how iPhones and iPads look and feel.

On the other hand, Microsoft is more restrictive than Google's open source system, which allows anyone to manufacture an Android handset however they want (which entails risks, such as letting Android become associated with poorly-made devices).

Microsoft licenses Windows to other companies, and imposes certain conditions on the devices they produce. It hopes to ensure a minimum level of reliability and quality, while still giving manufacturers freedom to develop their hardware creatively.

The minimum requirements for Windows 8 tablet computers require device to contain at least one USB port and Bluetooth support, along with features such as accelerometers (to detect tilting and rotation), speakers, and wireless networking.

Windows Start Button At Your Fingertips

Perhaps the most surprising requirement is a physical button, of a specific size and location, which functions like the Start icon on Windows 7 computers. Experts believe this requirement is as much about branding as about providing usefulness for users. (Source: pcmag.com)

There are a couple of notable absences from the requirements list, too.

While both the display and the camera must be capable of high definition, there's no actual requirement to include a camera at all. There's also no minimum requirement for battery life, a curious omission since poor battery performance could possibly sour users on the devices and provide a good reason for them to reject tablets running Windows 8. (Source: zdnet.com)