USPTO upholds Microsoft FAT patents

The U.S. Patent and Trademark Office (USPTO) has upheld two Microsoft patents for technology that controls how files are stored in the Windows OS, according to a Microsoft spokeswoman.

Earlier this week, the USPTO ruled that patents that cover the File Allocation Table (FAT) file naming system in Windows are valid after completing a re-examination of the patents at the request of both a public interest group and an individual, said Tricia Payer, a spokeswoman for Microsoft's public relations firm, Waggener Edstrom.

Payer said Microsoft received notices this week that the patent office was terminating its re-examination of the patents, Nos. 5,579,517 and 5,758,352, and issuing updated patent certificates for the original patents. The patents cover the ability to handle long and short filenames.

Microsoft claims it developed FAT in 1976 and was granted a patent on the file system in 1996. But some in the industry, particularly those with interests in developing and promoting open-source software, have disputed the FAT patents Microsoft holds. Microsoft licenses FAT to third parties, who must pay the software company to use it in their technology, Payer said.

Both the Public Patent Foundation, or Pubpat, and a California man named David L. Hoffman requested separately that the patents covering FAT be reexamined by the USPTO. Pubpat made its request in April 2004, and Hoffman made his in January 2005, according to USPTO documents.

The USPTO initially rejected patent 5,579,517 in September 2004 after reexamination, but Microsoft submitted more materials to support its claim on the patent.

The decision unveiled Tuesday is the USPTO's final decision, according to USPTO documents. The upholding of the patents means that Microsoft can continue to license FAT to third parties for a fee.