After two years of forcing the virtues of Windows Vista on the channel and IT marketplace, Microsoft head honcho Steve Ballmer finally admits the ill-fated operating system is a failure and that it’s tarnished his company’s reputation.

Why was Vista a failure? Ballmer blames security.

"We got some uneven reception when [Vista] first launched in large part because we made some design decisions to improve security at the expense of compatibility. I don't think from a word-of-mouth perspective we ever recovered from that," Ballmer told the British newspaper The Telegraph.

In the months leading up to Vista’s 2007 launch, Microsoft channel executives crisscrossed the country giving talks and meeting with partners about how the new operating system would be more adaptable, stable and secure than previous iterations. The long lead time for the Vista launch was intended to give ISVs and hardware partners time to write new drivers for Vista. What Microsoft was trying to do is short-circuit the typical 18-month adoption cycle seen in previous Windows releases.

Microsoft did make a conscious choice in turning off numerous services that many third-party applications and hardware devices relied upon to operate. The interoperability and compatibility issues caused many companies to forego upgrading to Vista and remain on the more friendly and adaptable XP platform.

Vista’s failure and Ballmer’s faulting security is a bit of being careful for what you wish. Vista (codename “Longhorn” during its development) was always intended to be a more secure operating system. Following the security disasters and 2000 and 2001 that befell Windows 98 and 2000, Microsoft shut down all software development and launched the Trustworthy Computing Initiative that advocated secure coding practices. Microsoft retrained thousands of programmers to eliminate common security problems such as buffer overflows. The immediate result was a retooling of Windows XP to make it more secure for its 2002 launch. Long-term, though, was to make Vista the most secure operating system in Microsoft’s history.

What made XP and Vista more secure? Eliminating (or reducing) buffer overflow errors helped. But what really made a difference is shutting off services by default. Many of the vulnerabilities exploited in Windows 98, NT and 2000 were actually a result of unused services that were active by default. Microsoft’s own vulnerability tracking shows that Vista has far less reported vulnerabilities than any of its predecessors. Unfortunately, a Vista locked down out of the box made it less palatable to users.

Now security obstacles aren’t the only ills that Vista suffered. Huge memory footprint, incompatible graphics requirements, slow responsiveness and a general sense that it was already behind competing Mac and Linux OSes in functionality and features made Vista thud. In my humble opinion, the security gains in Vista were worth many of the tradeoffs; and it was the other technical requirements and incompatible applications that doomed this operating system.