Is June 18 the end of the line for Windows XP? Not quite.

After a 5-month stay of execution, the end is nigh for Windows XP.

Tomorrow, June 18, will be the last day you can purchase a Dell computer with XP pre-installed. Dell has announced this in order to meet Microsoft's June 30 deadline for ceasing sales of XP.

I spot-checked other manufacturers' sites and found limited availability of computers, mainly business-oriented models, available with XP. Compaq and HP together offered at least 11 laptops and 7 desktops, Lenovo a couple of laptops, and Sony one model. I couldn't find any Gateway models with XP.

Microsoft had originally intended to kill XP this past January in order to give its heir, Vista, total reign over the PC market.  But an outcry from consumers and businesses  (and manufacturers looking to appease them) stayed Microsoft's hand for five months to give XP users time to warm to the beleaguered Vista.

Says Microsoft to Vista detractors:

"We love that you love Windows XP…But our commitment to innovation sometimes means making tough choices. This is one of them."

Despite the tone of finality, Microsoft has left open several loopholes so that XP lovers can hang onto it for some years to come.

If you're a business user:
XP downgrades will still be available to business users after buying Vista.  A popular option for users not ready to quit XP, individual manufacturers can sell PCs with versions of Vista and Windows XP Professional both included.  Dell, for example, is selling machines with XP preloaded and installation media and support for Windows Vista Business or Ultimate, dubbed the "Vista Bonus option."

The downgrade option is available only with Vista Business and Ultimate systems (not Home Basic or Home Premium) and even then you can only downgrade to XP Professional (not XP Home Edition or XP MCE.)

But home users have an option, too:
Microsoft will continue to make Windows XP Home edition available for "ULCPCs" (that is, ultra-low-cost PCs) through mid-2010.

ULCPCs are a relatively new type of mobile computer designed for people who want to complement their primary computer with a more limited device. They generally have smaller screen sizes and slower processors, which are fine for basic tasks like word processing and e-mail.

Microsoft says that extended support—free security updates and for-pay, per-incident support—will be available for all versions of XP through April 2014.

There's no reason for most people to shy away from Vista when buying a new Windows PC. However, you might consider using XP if you're on a tight budget, engage in very few risky online activities, and aren't anxious to learn the quirks of a new Windows user interface. Geeks may appreciate XP as a "leaner" OS that runs a bit faster when performing complex tasks, and offers more development possibilities for multimedia, Windows programs, and the Web.  A seasoned PC user might also be turned off by Vista's habit of nagging you whenever you install a new program.

—Nick K. Mandle