Redmond (WA) - Microsoft has reportedly begun offering a downgrade option to PC makers who want to allow their customers to have the option of using XP over the pre-installed Vista software.

Computer manufacturers including Fujitsu, Lenovo, and HP now mainly offer PCs exclusively with Vista pre-installed. Customers who would prefer to have XP can request a downgrade disc for computers that come with Vista Business and Vista Ultimate. These two versions allow downgrading as part of the software licensing, but the process is difficult without a specifically coded disc.

Several big PC makers never stopped offering XP as an option for custom-built computers. However, the standalone operating system software has nearly vanished from all retail outlets.

The new policy dates back to June, when Microsoft caved in to allow the manufacturers to include a special XP downgrade CD with systems that come pre-loaded with one of the two high-end Vista packages. Per Microsoft's licensing terms, it is not obligated to supply earlier versions of its operating system to consumers or manufacturers.