The scheme, launched in September for English language users of Windows, asks visitors to the Download Center (as opposed to the Windows Update site) to check that the Windows software installed on their machines is a legitimate and licensed copy.
If it is, the user is given access to downloads and updates available on the site. If it is not, then the user still gains access to the material, but first has to wade through some details on software piracy, educating him on the law and the greater reliability, faster access to support and all-round richer experience of legal software.
The pilot has proved very successful, with over five million users voluntarily taking part since the launch.
Microsoft now plans to expand the scheme. From 7th February, 20 new language versions of Windows XP and most of the Windows content found on the Download Center will be added to the opt-in trial.
But Download Center users with Norwegian, Czech and Simplified Chinese language versions of the operating system will find themselves forced to participate in the program, if they wish to access genuine Windows content, said Microsoft.
Microsoft is also piloting a legalisation offer in the People's Republic of China, Norway and the Czech Republic, where software piracy is said to be rife. Qualified participants from these countries are invited to have their copies of Windows XP analysed, with the offer of a genuine version at a reduced price if it is found to be counterfeit.
The offer follows a similar validation exercise run in the UK late last year.
Microsoft is also encouraging participation in the scheme through new software incentives, to a value of over $450, it said.
The voluntary nature of the scheme as a whole is due to change in the second half of the year, when participation in Windows Genuine Advantage will be required from all visitors to the Microsoft Download Center and Windows Update who wish to access downloads and updates.
To help customers who may require more time to move to genuine Windows software, Microsoft said that it would offer security updates through Automatic Updates in Windows, with or without Windows Genuine Advantage validation.
