Microsoft will provide hardware partners with media to let their customers downgrade from Windows Vista to Windows XP for six months longer than it originally planned, the company confirmed Friday.

The move comes even as Microsoft has just launched a US$300 million marketing and advertising campaign to encourage people to buy Windows Vista. The company is also prepping Windows 7, the next client version of the OS, for release in the next 12 to 18 months.

Microsoft will give OS disks to OEMs (original equipment manufacturers) and system builders so customers that purchase Windows Vista Ultimate and Business editions can downgrade to XP Professional if they so choose until July 31, 2009, Microsoft said through its public relations firm.

Previously, Microsoft planned to provide the XP recovery disks to partners until Jan. 31, 2009, although there is no deadline for downgrade rights, the company said. If a customer wants to downgrade from Vista to XP after the new deadline, they can contact Microsoft for a disk, the company said.

A published report revealed Microsoft's extension of the XP media deadline early Friday, citing an OEM source.

Microsoft predicted that Vista, which was released on Jan. 31, 2007 and took more than five years to develop, would be the most successful launch of its Windows client OS. However, Vista has been riddled with glitches and bad publicity, and many businesses and consumers still prefer XP.

The IDG News Service is a Network World affiliate.