By Katie Marsal

Published: 09:00 PM EST

In spite of a marketing deluge, Microsoft's latest operating system has yet to see adoption by any but the most dedicated enthusiasts, news reports say -- and it may be scaring off potential customers through draconian licensing.

Although the Redmond-based developer crafted a series of publicity stunts to promote Vista -- its first significant upgrade to Windows in well over five years -- first-day reactions to the much-ballyhooed system software were lukewarm at best. A skyborne dance routine in Manhattan and elaborate laser show in Shanghai did little to "wow" prospective owners as Microsoft's marketing campaign had promised.

Many stores that had planned midnight showings were surprised at the lack of devotees queuing up to buy Vista. CompUSA's premier store on San Francisco's Market Street only saw a fraction of the 500-plus shoppers its manager had hoped for at the stroke of twelve. And in an unintentionally hilarious piece of irony, many of those who came to shop -- including those at the head of the line -- were there only for discounts on gadgets rather than Microsoft's software darling. Similar stories surfaced in other parts of the US.

Indeed, Microsoft's claim to the biggest Windows launch ever were undermined by its own business. The size of the launch has already been dismissed as the result of natural momentum: with more Windows users already in the market, Vista is guaranteed almost by default to sell more units than XP as more owners exist to buy upgrades or replace old systems with new ones, The Washington Post learned from analysts.

"This is going to be biggest version of Windows ever. But that's just inertia," said research firm Gartner's Steve Kleynhans. "Will it really dominate the market or change the market in the way earlier versions of Windows did? It remains to be seen."

The software giant may even have inadvertently discouraged the technically savvy from buying into its plans by seemingly punishing those who buy upgrade copies of Vista. A thorough look at the End-User License Agreement for the Microsoft package has revealed that the license key for an existing version of Windows becomes invalid the moment a Vista upgrade is installed. This would all but make it illegal in the company's eyes to use the earlier software, even on the same system as part of a multi-boot solution.

Microsoft hadn't said in the EULA that it would deliberately block activations of new Windows XP installs, but has already taken heat from the Internet community for allegedly driving honest upgrade buyers towards full-sized (and thus more expensive) copies of Vista. When combined with the newly-added hassle of installing the old OS instead of simply validating the old disc as in the past, many are asking just who, if anyone, Redmond hopes to entice with its much-delayed refresh.