Competition Commissioner Neelie Kroes sent a letter to the software maker last week outlining two main concerns regarding Vista and its conformity with the Commission's March 2004 decision, according to a statement from the Commission on Wednesday.
One concern centered on the possibility that Vista would include features in its products that are already available separately from Microsoft and other companies, such as Internet search, digital rights management and software to create fixed document formats like PDF.
The other concern focused on whether Microsoft would fail to disclose all necessary technical information to third parties to make Vista interoperable with competing products.
The European Commission will begin aon allegations that Microsoft failed to comply with its . The issue of having Microsoft's OS interoperable with competitors' products is also at the heart of that ruling, and the Commission will decide whether the software giant should be subject to a fine of up to 2 million euros a day.
While the Commission sent the Vista letter as a means to clarify its concerns, the European antitrust regulators have not formally launched an investigation.
Microsoft, meanwhile, contends it is working hard to be inclusive with Vista.
"Keeping the industry and regulators informed of our product development plans has been, and will remain, a priority," Microsoft said in a statement on Wednesday, noting it has not yet received the Commission's letter. "We have worked hard to include partners and competitors in our planning, so they can build products and services that work with Windows Vista."
Other industry players, however, have raised objections to the lack of interoperability of Microsoft's older OS with their products.
The European Committee for Interoperable Systems (ECIS) will submit evidence at the hearing this week, as an interested party. The ECIS includes Sun Microsystems, RealNetworks, IBM, Oracle, Corel, Nokia, Red Hat, Opera and Linspire.
The "industry wants nothing more than to achieve interoperability as soon as possible to restore consumer choice and competition on the merits in the work group server market," Simon Awde, ECIS chairman, said in a statement. "Two years after the Commission decision, we are still not there."