Not long has passed since Microsoft’s long awaited Vista operating system has been released and its anti-piracy security system has already been cracked.

As advertised, Windows Vista implements a series of security measures meant to stop the software piracy that is affecting the operating system and thus Microsoft’s income out of it’s main product.

One of these measures require users of the corporate version of Vista to activate their copy with the help of a tool called Key Management Service which allow a company to run a Microsoft-supplied authorization server on its own network and activate Vista without contacting Microsoft for each copy.

Hackers have spoofed Microsoft’s Key Management Service (KMS) server which allows corporations with 25 or more networked computers to activate Vista installations and now the file which contains the hack is being distributed over the Internet.

The hack, named after Bill Gates’ wife – Melisa Gates, lets users spoof that KMS process, allowing them to activate copies of the enterprise editions of Vista and use them for 180 days, until the software requires reactivation.

Microsoft did not respond to requests for comment on the hack.