Attorney Van der Wal wouldn't speculate on the next step in the legal case. "The question is what priority the European Commission attributes to this complaint. Does it deem this to be of great interest to society or not? I can imagine that this is of great interest because it harms Europe's competitive position. Companies and citizens are overpaying on their software by billions of euros."

The antitrust complaint doesn't affect Microsoft's case against Abdalla, which was filed in Los Angeles. Abdalla declined comment on that case.

Microsoft didn't respond to a request for comment on the antitrust suit over the course of two days. The company typically doesn't comment on pending litigation.