EU've been a bad boy Microsoft...

... at least we think you have and now need to prove it.

European Commission experts have concluded that U.S. software giant Microsoft violated EU antitrust rules, but their proposed remedies need refining to withstand court scrutiny, sources familiar with the case said.

The experts have proposed two major requirements--making Microsoft share more proprietary information with its rivals and uncoupling its Media Player audiovisual software from the ubiquitous Windows operating system, sources told Reuters.

Both suggested remedies would go beyond changes agreed with the U.S. Justice Department last year after courts found Microsoft had abused its Windows monopoly.

The EU's Microsoft case is still months from a conclusion, but an internal Commission review of the experts' initial findings has thrown up doubts about whether the recommendations will be watertight both legally and technically, the sources said.

View: EU stymied over Microsoft antitrust case