Microsoft will remove a controversial anti-piracy tool from Windows Vista which disabled most the operating system if it considered that a user did not pay for a copy of the software.

The tool had been a source of frustration to some users, who have complained that the tool sometimes disables legal copies of Vista.

The changes to Vista will be included in an upcoming update package which users will be able to download in the first quarter of 2008.

With the updated system, users will get pop up messages notifying them about the status of the software along with information about how to make the software legal.

Users whose systems are identified as counterfeit will be presented with clear and recurring notices about the status of their system and how to get genuine copies, Microsoft said in a statement.

Microsoft has said that its efforts to reduce piracy have been successful, reducing fake copies by half compared to the previous version of the system, called of Windows XP.

The software used to check the system is called Windows Genuine Advantage.