With the Blaster worm seeming to be under control, alleged virus-author Jeffrey Parson under house arrest in Minnesota, and hacker Adrian Lamo under the watchful eye of the feds, business-technology managers may have enjoyed a few hours of peace and quiet last week. But it was short-lived. On Sept. 10, Microsoft issued a security bulletin warning of three new critical vulnerabilities in the Windows operating system, sending systems administrators rushing to patch their computers. It's become an all-too-common scenario--and one that's causing some businesses to re-evaluate their heavy reliance on Microsoft products.

A year-and-a-half after Bill Gates declared that trustworthy computing had become Microsoft's No. 1 priority, the software bugs keep coming. The latest vulnerabilities involve the Remote Procedure Call service in Windows, making it possible for a malicious hacker to take control of a target system, introduce an infectious worm, or launch a denial-of-service attack. A week earlier, Microsoft issued five other warnings, four involving the omnipresent Office applications suite. For the year, the tally stands at 39.

And those are just the holes that have been uncovered by others and reported to Microsoft. In addition, the software vendor is combing through its code, finding holes, and issuing patches without publicizing the flaws. No one knows how many more are yet to be uncovered. "There's no way to wrap your hands around that," says Dan Ingevaldson, engineering manager with security vendor Internet Security Systems Inc.

"You have to seriously start thinking about alternatives," Bowne CIO Harenchar says. Photo by Jean-Christian Bourcart/Getty Images

Some business and technology professionals are running out of patience. "The issues around these vulnerabilities are escalating to the point where it's not just CIOs or CTOs, it's corporate officers, it's boards of directors asking: 'What are we going to do?'" says Ruth Harenchar, CIO of Bowne & Co., which last week scrambled to patch 4,500 Windows PCs and 500 servers in the United States and more overseas. "The situation appears to be getting worse, not better."

The patching work has thrown Bowne & Co.'s technology projects off schedule. Now, the specialty-printing-services company is assessing its options. Among them: redesigning its network around a thin-client model to reduce the number of PCs running Windows and, on other machines, migrating to Linux. "It's getting to be enough of a burden that you have to seriously start thinking about alternatives," Harenchar says.

Raymond James & Associates has assembled a team of IT staffers to manage the constant patching. "Organizations have to mobilize and realize this is going to be a way of life for the foreseeable future," says VP of IS Gene Fredriksen.

The financial-services firm, with offices around the world, last week began the arduous task of patching 10,000 PCs and 1,000 servers. "The pressure is on," Fredriksen says. "Anybody that isn't patched by the weekend is going to have trouble." The fear is that the latest vulnerability leaves Windows computers open to a Blaster-like worm. "There's a very good chance that a worm is going to be developed" to take advantage of the latest security holes, says ISS's Ingevaldson.

"People are getting fed up," says Lloyd Hession, chief information security officer at financial-network provider Radianz, adding that the number of Windows patches is reaching "epic proportions." The situation is causing more than just a few disgruntled customers to re-evaluate how much they use Microsoft products. Says Gartner security analyst John Pescatore, "There's definitely a very large trend towards that."