Microsoft has filed a second appeal against a European Union ruling that stated it had to give rivals greater access to its operating systems.
In March 2004, the world's biggest software firm was found guilty of abusing its position, hit with a record fine and told to open up its systems.
Microsoft has appealed against the fine and now wants to avoid giving more information on its server programs.
The firm argues that doing so would violate intellectual property rights.
"We are taking this step so the court can begin its review now of this issue given its far-reaching implications for the protection of our intellectual property rights around the world," Microsoft spokesman Tom Brookes said.
'Back to court'
At the heart of the argument is the way that computer servers are set up and how companies can use the computer code that runs them.
Many of the best-selling, and industry standard, servers are based on open-source software - meaning their operating code is shared and freely available.
The way Microsoft operates is different, in that it does not give companies full access to the underlying code, preferring to keep that secret.
That practice has to stop, according to the EU.
As part of its March 2004 ruling, the EU also ordered Microsoft to provide a version of Windows operating system without its own Windows Media Player.
"If they do not share our point of view, they are of course free to go back to the court if they want to," said EU spokesman Jonathan Todd.
Microsoft has asked the Court of First Instance in Luxembourg to rule on the server issue.
The court can decide whether to treat the new appeal as a separate court action, or join it to the one filed last year.
Whatever the decision, it is unlikely that the case will be resolved fully until 2007 at the earliest.
In the meantime, rival server companies are complaining that they have been caught in limbo and have argued that by the time the case is settled the technology will have moved on.