In a bid to clamp down on software pirates, Microsoft yesterday began emphasising the potential security risks posed by pirated software.

Pirated software in some cases comes bundled with spyware or contains bugs that affect system stability, the Redmond vendor warned.

There are also known cases in which websites promising discounted software are actually set up to steal credit card information.

"It used to be that we were dealing simply with unlicensed counterfeit copies of software, which hurt Microsoft and the ecosystem of partners that makes a living selling our products," said Cori Hartje, Microsoft's director of licence compliance.

"Today the problem is much bigger, and it's our responsibility to do whatever we can to help protect consumers and ensure that they are purchasing and using genuine Microsoft software."

Microsoft plans to continue investing in anti-counterfeiting technologies in its software, including Windows Genuine Advantage which blocks access to certain free downloads to users of pirated copies of Microsoft software.

The vendor also plans to step up its legal battle against organisations involved in counterfeiting software.