A week into the release of Windows Service Pack 3, Microsoft Chief Steve Ballmer is saying the company could re-consider phasing out of its most widely-used operating system Windows XP after June 30, if customers so desire. Ballmer was speaking at the Louvain-La-Neuve University in Belgium.

In September last year, Microsoft had said it would stop licensing Windows XP to computer makers and end retail sales by June 30, reason being the high degree of demand amongst consumers for the OS.

Even with the latest announcement, Ballmer has been quick to add that while they could re-consider phasing out of Windows XP after June 30 if the customers so wish, in actuality, that’s not the case: most retailers are selling PCs with Vista and most customers are also opting for Vista over XP. Ballmer said customers buying PCs with XP are more often than not corporate IT departments faced with the problem of shifting older machines to newer technology.

All said, if the recent crowding of Internet space by fans of Windows XP is any indicator, Windows XP still enjoys fair demand in the market. A petition titled “Save XP Web” launched by Galen Grumman, executive editor of InfoWorld, has garnered support from some 165,000 people till date; as the name suggests, it demands that Microsoft continue selling XP until the next version of Windows is out, currently scheduled for 2010.