Computerworld — Even though it has had its own problems of late, Windows XP remains the most-used version of Windows. The newest data from Web metrics vendor Net Applications Inc., for example, pegs XP as driving 73% of the personal computers that went online last month, five times the nearest competitor, Microsoft Corp.'s own Windows Vista.

Which is why an impending deadline five weeks from today is important.

According to Microsoft , June 30 is the last day it will permit retailers and OEMs to sell the nearly-seven-year-old operating system.

You'll have questions as that date approaches, including whether the deadline will drive up prices (gouging, anyone?). And we plan to have the answers, starting with this FAQ and continuing through the end of next month.

How long until Microsoft shuts off the XP spigot? Five weeks from today is the last day Microsoft will officially allow retailers to sell the old operating system and let major computer makers—called "OEMs," for "original equipment manufacturers"—to sell PCs with XP pre-installed.

Monday, June 30, is the EOL—or End-Of-Life, a term Dell Inc., not Microsoft, has publicly used—for XP's retail and OEM availability.

So what's the June 18 date I've heard about? That's the day that Dell has said is the last possible day for its customers to buy a machine running Windows XP. "To meet Microsoft's June 30 last-day-to-ship OEM Windows XP deadline, June 18 is the last time to purchase a Dell laptop, desktop, or workstation with an OEM Windows XP license," Dell says on its Web site.

Other big-name OEMs, such as Hewlett-Packard Co. and Lenovo Group Ltd., have not announced cutoff dates, but they must also abide by Microsoft's rules that no XP-based system can ship after June 30.

Are there any loopholes? Sure, and they're big enough to steer the Titanic through. A "downgrade" clause in Microsoft's guidelines for OEMs lets computer makers install Windows XP Professional—but not the more common and less expensive Windows XP Home—on new PCs at a customer's request when those machines are ordered with Windows Vista Business or Windows Vista Ultimate.

Dell took advantage of the clause to announce last month that it would use the downgrade rights of Vista Business and Vista Ultimate to install XP Professional free of charge at the factory. Assuming customers want to, they can later use the included Vista installation media to upgrade from XP Professional.

Other vendors are doing similar things. HP, for example, also offers a free at-the-factory XP Professional downgrade option on some systems sold with Vista Business.

Continue Reading