By AppleInsider Staff

Published: 04:05 PM EST

In a crushing defeat for the clone Mac maker, Psystar was on the losing end of a crucial court decision in the company's ongoing legal battle with Apple.

Judge William Alsup ruled this week in a summary judgment that Psystar infringed on copyrights owned by Apple in order to place Mac OS X on unauthorized computers built and sold by the Florida corporation. In addition, Psystar was found to be in violation of the Digital Millennium Copyright Act by circumventing Apple's protection barrier that prevents installation of its operating system on third-party hardware.

"Psystar infringed Apple's exclusive right to create derivative works of Mac OS X," the ruling reads. "Specifically, it made three modifications: (1) replacing the Mac OS X bootloader with a different bootloader to enable an unauthorized copy of Mac OS X to run on Psystar's computers; (2) disabling and removing Apple kernel extension files; and (3) adding non-Apple kernel extensions."

Alsup also denied Psystar's own motion for summary judgment, in which the company attempted to prove that Apple engaged in copyright misuse. The judge ruled that Apple's End User License Agreement only attempts to control use of Apple's own software, which is within its rights.

The summary judgment does not mean that the trial is concluded, however. A number of issues remain to be resolved. Apple has alleged that Psystar has engaged in breach of contract, trademark infringement, trademark dilution, and unfair competition, among other activities.

The ruling was issued Nov. 13 in a San Francisco court. Another hearing has been scheduled for Dec. 14, and trial between the two companies is due to start in January 2010.

The decision came after both companies requested summary judgments, which turned into a positive for Apple and a significant defeat for Psystar.

It's just the latest of many setbacks for Psystar as it has attempted to defend itself from Apple's suit. In September, a member of the Psystar defense team withdrew himself from the case. And in July, the Florida-based corporation brought on a new legal team after it emerged from bankruptcy.

The company -- which sells machines with Snow Leopard, Apple's latest operating system, preinstalled -- in October began to license its virtualization technology to third-party hardware vendors. The Psystar OEM Licensing Program intends to allow Intel machines made by companies other than Apple to run Mac OS X 10.6.