WASHINGTON -- In a case that echoes earlier fights over terms like "Light Beer" and "The Pill," the federal government has issued a preliminary decision denying Microsoft Corp. a trademark for the word "Windows" on its hugely successful computer program by that name.
If it is upheld, the decision by the U.S. Patent and Trademark Office, which Microsoft will appeal, would be a blow to the software giant. Microsoft dominates the market for programs that provide the basic instructions on IBM-compatible personal computers.
Developed largely so that IBM computers could become as easy touse as Apple Computer's Macintosh line of machines, Windows has become a wildly successful product in its own right.
In the last year, Microsoft has sold more than 12 million copies of Windows, which allows someone to use more than one program, such as a word processor and a tax program, at the same time and to move easily between them without having to type arcane commands.
Windows displays the individual programs in small rectangular frames on a single screen and has spawned a software industry of companies that tailor programs to run with it. Windows and associated programs are now widely used in offices and homes.
If Microsoft loses the trademark battle, it will have a much more difficult time fending off imitators that promote their products with variations of the same name. Company officials say customers would be in danger of buying inferior products and that rivals would effectively get a free ride at Microsoft's expense.
Microsoft has been trying to require programmers who create software for Windows to obtain licenses that give Microsoft some control over the content of the programs.
Opponents of the software giant, which is now the target of an antitrust investigation at the Federal Trade Commission, argue that it is trying to carve out exclusive use for a word that is as common in the computer industry as "sudsy ammonia" was in cleaning compounds or "the pill" in contraceptives.
Both names were rejected by the Patent Office over the years, as was "Light Beer," which Miller Brewing Co. attempted to register as a trademark.
In a detailed, 31-page letter issued last week, the Patent Office sided strongly with Microsoft's opponents. The letter argued at length that the word "windows" has a generic meaning in the computer industry and was in use long before Microsoft introduced its product in 1983.
Microsoft officials minimized the importance of the letter, saying that it represented merely one step in a long process. The company has six months to try to persuade the Patent Office to change its mind. If that effort fails, the company may challenge the ruling before the agency's board of appeals and then take the matter into federal court.
Jonathan Lazarus, vice president for strategic systems at Microsoft, said the company was trying to protect its hard-earned name and prevent consumers from being fooled by inferior copycat products.
But the federal agency's letter said that "the evidence clearly demonstrates that the public understands the term 'windows' to mean a genus of goods, namely computer software which utilizes windows on a computer screen."
Microsoft allows hundreds of companies to use the Windows name and logo on software products that work with its program and on publications about it. The company does not charge royalties.
But it requires programmers to obtain a license, sets out rules for "proper use" of the logo and requires that every software product bearing the logo be indeed technically compatible with the Windows program.
Officials at Borland International, in Scotts Valley, Calif., argue that Microsoft is using the trademark as a tool to retain control over the software market. Borland has applied for trademarks on the names Borland Windows and Turbo Windows.