Microsoft is clamping down on pirated software with the introduction of a Windows Genuine Advantage program that means you must have a legitimate copy of the operating system to benefit from downloads and updates from its website.

Although the fear has always been present that Microsoft track who has downloaded what, the company never has, up until now.

According to Microsoft the program actually started in September last year with a voluntary registration program. Now 5 months on and the company has got 5 million of the 8 million users signed up.

In an extra attempt to convince users that signing up is actually a good thing Microsoft has included software incentives. Windows XP users will get Microsoft Photo Story 3 for Windows, Winter Fun Pack 2004, a six-month trial of Office OneNote 2003 and discounts on select MSN Games by Zone.com, Windows SharePoint Services, List Builder and Office Outlook Live.

The drive by Microsoft is an attempt to drastically reduce the amount of pirated software by simply not supporting it after its been installed. Users of the malware will be more open to virus attacks and security holes that haven't been patched.

Microsoft has also begun a program to allow users in China, Norway and the Czech Republic who have counterfeit versions of XP to buy the software at a discount.