Symantec on Thursday sued Microsoft for what it said was improper inclusion of its intellectual property in Windows Vista, and asked a federal court in Seattle to block distribution of Vista until Microsoft changes the software. Microsoft said the claim was without merit and that its actions are "proper and fully consistent" with a contract it signed with Veritas Software, which Symantec acquired last year. The dispute centers on software technology that allows an operating system to store and manipulate large amounts of data, and recreate files after a disk storage failure. Symantec claims that Microsoft violated terms of a 2004 contract under which Microsoft licensed this type of software from Veritas, by using it to develop competing products. Symantec said technology in Microsoft's upcoming Windows Vista operating system, due next year, misappropriates trade secrets found in its Volume Manager product, which it gained when it bought Veritas. Symantec went to court to stop Microsoft from developing or distributing Vista until Microsoft removes the intellectual property.