NEC has developed a laptop computer targeted at corporate users that doesn't include a hard disk drive, it announced on Wednesday.

The 'PC Parafield' has been developed as a replacement for existing thin-client systems and combines both high data security with the ability to be used anywhere, said Hitoshi Onodera, a spokesman for the Tokyo company.

Conventional laptop computers can work anywhere but represent a potential security threat if they are lost or stolen. Thin-client systems get around this by working off a corporate server. However, they require a network connection to work properly, and such a connection is not always available, Onodera said.

The NEC laptop attempts to combine the strengths of both systems while avoiding the weaknesses, he added.

The OS (operating system) and application software is all stored locally in flash ROM so the machine can function in the absence of a network. Flash ROM is the type of memory typically used to store a PC's Bios or the firmware in electronics devices and allows limited reprogramming.

Local storage is provided in the computer's RAM, which is cleared when the machine is switched off, thus removing any potential security risk from data theft but also requiring a backup before the computer is switched off. This can be done with a central server or, should a network not be available, to a USB memory device, Onodera said.

From the outside, the PC Parafield looks like a standard B5-size laptop computer and its specifications are fairly standard, except for the absence of a hard drive.

The machine is based on an Intel Pentium M processor running at 1.73GHz and runs on the Windows XP Professional OS. It has 3GB of ROM space for the OS and other software and 512MB of main memory. The screen is an XGA resolution (1,024x768) 12.1in TFT LCD. It also has a PC Card slot, an Ethernet socket and a USB 2.0 port.

The laptop measures 275x233x25mm and weighs 1.3kg.

The computer is available immediately in Japan for ¥448,000 (about £2,190). NEC said this works out as cheaper on a per-user basis than a thin-client system because the PC Parafield doesn't require a company to deploy a comprehensive network access system or central server.

At present, there are no plans to sell it overseas.

"We haven't heard of another company offering such a product so at first this is something like a concept product," Onodera said. "We'll launch it and see what the market response is before considering an international launch."