From now on, customers looking to get the latest add-ons to Windows will have to verify that their copy of the operating system is legit.
Beginning Tuesday, the piracy check will be mandatory for all customers worldwide who want to download add-ons for Windows XP.
The only exception is for security-related patches. Regardless of whether a system passes the test, security updates will be available to all Windows users via either manual download or automatic update. The Microsoft Update and Windows Update utilities, which provide notifications of new patches, will require validation.
It's all part of Windows Genuine Advantage, a stepped-up effort by Microsoft to increase the number of Windows users that are actually paying Microsoft for its software. Currently, the company estimates that roughly a third of Windows copies worldwide are not legitimate.
Microsoft has been testing the Windows Genuine program since last September. At first, the program had neither benefits for those who passed inspection nor any penalty for those who failed or opted not to go through the piracy check. Gradually, though, Microsoft has been adding perks and moving to make the process mandatory.