Microsoft has "tweaked" its antipiracy software for Windows XP for English speakers, and has begun rolling out the optional tools to users in 21 additional countries - some of which the company has referred to as centres of counterfeiting.

The Windows Genuine Advantage Notifications software - which verifies that a copy of Windows XP is legitimate, offers up options to users running phony software, and prevents those who won't pay up from downloading non-critical updates - has been updated, a company spokesperson said today.

"While this release includes small enhancements, the overall experience is the same," she added.

Last November, David Lazar, the director of Microsoft's Genuine Windows programme, said the Notifications tool would be updated every 90 to 120 days through Windows Update. The newest upgrade is part of that process, the spokesperson said.

The Notifications tool is also being delivered for the first time to Windows XP users in 21 localised editions, ranging from Chinese (three versions) and Portuguese (two versions) to Russian and Korean. Some of those countries have long-standing traditions of counterfeiting software; in fact, Microsoft CEO Steve Ballmer recently named Brazil, China, and Russia as pirate havens when he said the company might "dial up" the intensity of its WGA efforts.

Other WGA changes include a revamp of the website dedicated to the antipiracy technology. New, too, are web-based diagnostic tools meant to help users troubleshoot problems with the WGA software.

Even though it's delivered to users via Windows XP's Automatic Updates - something analysts and users have criticised in the past - Notifications remains optional. That's not the case with Windows Vista; the new operating system boasts built-in anticounterfeit checks that cannot be disabled.

In Notifications' privacy and licensing agreements, Microsoft says that the tools "are designed to be permanent additions to your operating system" and "cannot be uninstalled".