Microsoft changes Vista anti-piracy system

Microsoft is removing the "kill switch" from its Windows Vista operating system, which is designed to stop PC owners from using illegal versions of Vista. The kill switch comes into action during the product activation process. If Microsoft's Windows Genuine Advantage anti-piracy system detects an illegal copy of Vista, the PC screen turns black and on-screen messages inform users that they are using an illegal copy. But Microsoft says that following "feedback" from partners and customers, the system will be revised.

Under the new system, which will be part of Vista's Service Pack 1, if an illegal copy of Vista is detected, users will not lose functionality, but they will see on-screen messages telling them to use a genuine copy. It's thought that Microsoft made this move after a number of users suffered "false positives" - genuine copies of Vista were wrongly identified as being fake.

Service Pack 1 will also aim to plug two holes that have been exploited by software pirates - altering the BIOS and system files to mimic the activiation process you get when using a pre-installed version of Vista on an OEM computer, and extending the activation period. Vista Service Pack 1 is due to arrive in early 2008.