Lindows.com launched MSfreePC.com in September as a way for California software buyers to get a piece of the settlement. The site offers Lindows software and Sun Microsystems Inc.'s StarOffice suite in exchange for a claim and the vouchers certain software buyers are entitled to under the settlement.

Under the settlement agreement, consumers with valid claims can use their proceeds to buy a wide range of hardware or software, including the Lindows operating system, Microsoft spokeswoman Stacy Drake said Monday. "We are concerned, however, that the Lindows Web site misuses the court-approved California settlement as a marketing tool for their products."