But some users at the show were more skeptical in their assessment of the company's progress and said it is too soon to deliver a definite verdict.

Ben Fathi, corporate vice president of Microsoft's security technology unit, gave the company's products a B+ for security during a panel discussion at the conference. Five years ago, he said, that grade would have been a C- or even a D.

The improvements are the result of a "cultural shift" at Microsoft sparked by Chairman Bill Gates' TWC memo of nearly five years ago, Fathi said. Since then, the company has completely overhauled its product development processes, and it has trained developers on how to write secure code, he said. The changes resulted in the development of a Software Development Lifecycle (SDL) process at Microsoft that every product has to go through.

"Last year, we had over 3,000 products that went through this and, with three exceptions, they all passed," he said. The products that failed were blocked from release while the development team fixed the problems or found a way to mitigate them, he said.

"Vista is the first product that has gone through SDL from inception to end," Fathi said. As a result, "there are a whole lot of improvements to security in the product."