Microsoft will offer an extra version of Windows Vista to European business customers when it launches the OS (operating system) later today.

The EC (European Commission) ordered Microsoft to release additional versions of Windows without its Windows Media Player software in 2004. The idea was to prevent Microsoft's dominance in the desktop OS market from giving it an unfair advantage over rivals such as RealNetworks and Apple.

That resulted in versions of Windows XP called 'Edition N', which sold for the same price as the standard Windows XP. With the release of Windows Vista, Microsoft is having to do the same again.

The company was still working with the EC to determine exactly how many N versions are required, but it expects to offer them for both home and business users, said Thor Windham-Wright, a spokesperson for Microsoft's public relations agency.

"To comply with the ruling, Microsoft will have to produce an Edition N for all future editions of Windows," confirmed Tom Brookes, Microsoft's spokesman in Brussels.

Microsoft releases Windows Vista Business and Windows Vista Enterprise to its volume licensing customers today, along with Exchange Server 2007 and the Office 2007 productivity suite. The consumer editions of Windows Vista are due for release on 30 January 2007.

Critics have noted that there has been little support from PC makers for the N versions of Windows, undermining the effectiveness of the EC's ruling. Most PC makers chose not to offer Windows XP PCs with Edition N, citing little interest from customers and the expense of supporting extra versions of the OS.