Vista may help stop some traditional types of attacks, such as worms, but Symantec maintains that newly emerging threats, integration problems with third-party Windows applications, and a range of other issues will keep users in the market for additional security tools.

One area that remains a sore spot from Symantec's perspective is Microsoft's use of new features to protect the Vista kernel against root kits and other attacks. In 2006, a major controversy broke out between the two firms and other security technology providers based on the fact that Vista's PatchGuard system, available only in 64-bit versions of the OS, prevents any programs -- including Symantec's security applications -- from patching the software's kernel memory.

Symantec and rival McAfee, among others, argued at that time that not being allowed to access the kernel as they have in prior iterations of Windows would prevent their advanced behavior-based technologies from working properly. But Microsoft and the security firms claim to have solved the problem using a set of APIs.

In the research reports, Symantec repeats its contention that PatchGuard may also be easily bypassed, defeating its very purpose and allowing kernel-altering attacks, including root kits, to live on.

Labeling the combination of PatchGuard and two other Vista kernel protection technologies, known as Driver Signing and Code Integrity, as a mere "bump in the road" for attackers, Symantec said that a single researcher bypassed all three features in one week's time, further proving their vulnerability.