Microsoft chief executive Steve Ballmer has told Wall Street analysts that the company might "dial up" the intensity of anti-piracy technology in Windows Vista as part of an effort to squeeze more revenue from emerging markets.

Ballmer's comments came during a conference call last Friday with financial analysts, in which he repeatedly hammered home the theme that sales forecasts for Windows – Vista in particular – have been "overly optimistic."

One way Microsoft can bump up Windows sales is to tighten the screws on pirates, Ballmer said. "Piracy reduction can be a source of Windows revenue growth, and I think we'll make some piracy improvements this year.

"We have new technologies built into Windows Vista, something we call Windows Genuine Advantage [that] we've really dialled up in capabilities with the Vista release," he said. "I do think that will bring some revenue growth. We will have strong growth in the Windows business in emerging markets: China, India, Brazil, Russia and many others. Those markets are very high piracy."

According to the Business Software Alliance, an anti-piracy watchdog group for the software industry, counterfeits accounted for 86% of the software sold in China, 72% in India, 64% in Brazil and 83% in Russia according to estimates for 2005, the last year for which data is available.

Last autumn, when Microsoft announced details of Windows Genuine Advantage in Vista – which included new counterfeit-sniffing software, as well as the crippling or disabling of important features such as the built-in anti-spyware protection and the Aero interface in bogus copies of the operating system – the company faced criticism from both users and analysts.

It appears that Ballmer doesn't agree, because he hinted that Vista's anti-piracy features might be tightened even more. "We [will] really ferret through how far we can dial it up, and what that means for customer experience and customer satisfaction," he said.

He also repeated the promise that Microsoft would not again make the mistake of taking half a decade developing the next Windows. "We won't go five years again, I promise, between big Windows releases," he said.

The promise replay was interesting because of its timing. Earlier this week, Microsoft distanced itself from remarks made earlier by a company executive that the next operating system would roll out in 24 to 30 months.