Worried about legal obstacles to the release of its upcoming Windows 98, Microsoft Corp. wants a federal appeals court to lift restrictions on its sale by computermakers. Pressed for time, the company asked for a court ruling by May 15.

In a legal motion filed in the U.S. Circuit Court of Appeals in Washington, Microsoft said restrictions that a federal judge placed because of antitrust concerns on the sale of Windows 95 "or any successor thereof" were "plainly improper."Microsoft this week has placed extraordinary emphasis on the importance of the timely release of Windows 98, a $109 upgrade to the operating system software that runs almost all home computers. It plans to offer the software to computermakers May 15 and wants to offer it at retail June 25.

The company and its supporters have argued that any interference with the sale of Windows 98 would hurt the entire computer industry.

But the Justice Department and a group of a dozen state attorneys general might try to block that sale. Both are investigating whether Microsoft has used its Windows muscle to illegally crimp competition, especially among Internet browsers.

On Wednesday, Microsoft released a poll it commissioned showing that 64 percent of 1,002 people questioned agreed that the attorneys general should not file a lawsuit that blocks Microsoft from releasing Windows 98. The poll, conducted by Hart-Teeter Research, had a margin of error of 3.2 percent.