The European Union’s top internet official took aim at Microsoft on Thursday, warning that governments can accidentally lock themselves into one company’s software for decades by setting it as a standard for their technology systems.

EU Internet Commissioner Neelie Kroes, in her previous post as EU antitrust chief, fined Microsoft hundreds of millions of euros (dollars) in a lengthy row over the company’s refusal to share some data with rivals and the tying of a web browser to a best-selling operating system.