Microsoft could face more EU fines for failing to comply with an anti-trust settlement to give Windows users a choice of web browsers.
The European Commission is looking into why the company failed to provide a screen with alternatives to its own Internet Explorer.
“We’re now opening formal proceedings against the company,” said Joaquin Almunia, the EU competition commissioner.
“If following our investigation, this breach is confirmed, and Microsoft seems to acknowledge the fact here, this could have severe consequences. Needless to say, we take compliance with our decisions very seriously”.
The browser choice screen has not been provided since February last year and Microsoft is blaming a technical error.
Firms can be fined 10 percent of yearly revenues for breaching settlements.
The EU has already fined Microsoft 1.68 billion euros in previous anti-trust probes.