Microsoft has filed legal papers in a California court requesting the rejection of all anti-trust settlement claims submitted with digital signatures.
The software giant also requested that the court reject all such claims that have been previously completed.
Michael Robertson, chief executive of Lindows.com, the sponsor of the MSfreePC service - designed to help plaintiffs file their own evidence against Microsoft - claimed that Redmond's move was designed to make it as difficult as possible for people to claim against the company.
"Microsoft is protesting [against] the same technology that people use to file federal and state taxes, order billions of dollars of merchandise online and that they themselves have used to generate billions in profits," he said.
But Microsoft said the open source firm was simply making mischief.
"We're concerned Lindows is using the settlement to push their own product," a spokesman for Microsoft told vnunet.com.
He said the stipulation that claims should be "printed off, physically signed and mailed in" was part of the agreement the firm struck with the claimants' attorneys as a means of avoiding any fraudulent claims, since the settlement does not require proof of the original purchase.
The settlement enables claimants to receive vouchers that can be used on a variety of softwares - both operating systems and applications - from a variety of vendors.
Lindows.com promised to "vigorously defend a consumer's right to use online technology to file claims" and said it would submit a legal opposition to Microsoft's motion within the next two weeks.
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