Microsoft is expecting a 20 per cent sales boost in China over the next year, following the country's clampdown on software piracy.

Licensed software has received a commercial boost from China's toughened stance on piracy, following complaints by Western governments and companies.

The past year has seen Chinese PC makers such as Lenovo and Founder, as well as global makers like HP and Dell, selling an increasing number of PCs in China with the Windows operating systems pre-installed.

Around 30 per cent of China's Lenovo PCs are now sold with pirated Windows systems, down from 90 per cent last year, according to Microsoft's chief executive in China, Timothy Chen. More than 20 million PCs were sold in China last year.

Microsoft's growth in the country has also been boosted by new products including the Vista operating system.