The WGA (Windows Genuine Article) programme will come into operation from the middle of 2005 and will help Microsoft's fight against counterfeit software. It could also help users check they have bought valid products.
Analyst firm Gartner said Microsoft's move would increase the importance of patching to business users. "If you allow users to install applications, ensure that the WGA process is safe and consistent with your security practices, especially if you rely on Windows Update to install security patches," said Gartner.
"The WGA program will inevitably result in more unpatched Windows systems available on the internet, so you must continue to improve your patching processes to protect your systems against worms and other malicious-code attacks spread by unpatched systems."
Security patches will initially continue to be available without validation, said Microsoft anti-piracy manager Alex Hilton. "If users do not succeed in validating the software, they will still have access to patches," he said.
Hilton said users found to have an invalid licence would be given the option of purchasing a legitimate one at a fee that would be less than the cost of the boxed retail version, but more expensive than an OEM licence.
Users would need to provide Microsoft with details of the supplier of the software to obtain the discount, Hilton said.
To launch the scheme, Microsoft is offering users a six-month trial of Microsoft Office Onenote and a 30% price reduction on the Outlook Live service.