Microsoft is giving system builders several more months to get Windows XP for their custom PCs, ensuring XP will be out in the marketplace until almost the scheduled release of Windows 7 in early 2010.

Microsoft confirmed Monday that it is offering a “flexible inventory program” that allows distributors and system builders to place their final orders for XP by the end of January, but have those orders delivered until May 30, 2009.

The company stressed in an e-mailed statement that the move is not “an extension of sales.” Still, it gives system builders and distributors the ability to sell PCs with Windows XP preinstalled for a bit longer than they currently have.

The move marks yet another extension Microsoft has had to made to keep XP in the marketplace, which customers have demanded because of lackluster reception for Windows Vista, XP’s successor, released to businesses in November 2006 and to consumers in January 2007.

Many enterprise customers have opted to skip upgrading to Vista and wait for Windows 7, which is expected to be available by the beginning of 2010. Even consumers have widely complained about how underwhelming Vista was, after all of the hype.

If Windows 7 is released in early 2010 as planned, it means that there will only be about a six- or seven-month gap between when the last XP machines will be for sale and when Windows 7 hits the market. And some feel that Microsoft may even get Windows 7 to businesses by the end of 2009 because the company recognizes it needs to repair the Vista damage.

In September 2007, Microsoft pushed back the date for when OEMs (original equipment manufacturers) could install and sell XP on PCs until July 31, 2008, from the original date of Jan. 31 of this year. At the same time, it extended the XP cut-off date for system builders until Jan. 31, 2009

XP has an even longer shelf life for the emerging ultra-low-cost PC (ULCPC) market, another concession Microsoft had to make because Vista’s hardware footprint was too big for these machines. In April the company said it would be available for OEMs to install on ULCPCs either until June 30, 2010, or one year after the availability of Windows 7, whichever comes first. (PC World)