Microsoft seems to always have had a rather turbulent relationship with the European Union. In March of 2004, the Redmond giant was found guilty violating antitrust laws. Despite their legal threats, the European commission stated that Microsoft did not properly comply with the ruling. In response to Microsoft’s lack of action, the European Union fined Microsoft $280.5 million in July for non-compliance. Microsoft, though, claimed that such fines were unnecessary and that they were trying to comply with the demands.

The Commission, however, has moved their interest from Windows XP onto Windows Vista. They EU Union stated that they are concerned in regards to Vista's built-in Internet search functions and new document features. The new search features are integrated with Microsoft’s online search engine. The commission threatened that if Microsoft would be displaying any more anti-competitive behavior in Windows Vista, a new case against them could be made.

Microsoft responded to the Commission by saying that if additional product design changes would be required, then Microsoft might be forced to delay Vista’s launch in Europe. Even though Microsoft hopes to have world wide availability, another design change in Vista will set the launch back for Europeans. Microsoft and their partners are reasoning that a Vista delay will only harm Europe. The European Parliament also expressed the same concerns; however, they have little control over the Commission's final decision.