"It is crucial that readers understand the difference between McAfee and those companies that focus on anti-virus software alone. Single-product vendors, like Sophos, may well not have an issue with Microsoft," said MacDermott.
"However, for an innovative security risk management vendor like McAfee, that offers its customers comprehensive security protection, full and unfettered access to the kernel is vital if we are to protect users as they are currently protected with XP."
The comments come after Sophos alleged that McAfee and Symantec should have prepared better to develop host intrusion prevention (HIPS) systems for Vista to protect against new malware.
Sophos said that its own approach to HIPS technology has met with no problems on both the low-spec and high-spec versions of Windows Vista. In addition, the security firm claimed that Microsoft has so far provided all the interfaces that Sophos needs for providing this form of protection.
MacDermott rejected these charges, pointing out that independent security developers have being partnered with Microsoft for several years to ensure that their offerings integrate effectively with Redmond's products. However, she argues that all that seems to have changed with Vista, because Microsoft is denying computer security companies access to Vista's underlying technology.
"Microsoft's flawed logic will only result in making computers more vulnerable to viruses and other attacks because we will not able to get into and monitor the kernel, which allows us to provide security at the operating system level," she added.
"To protect customers from the bad guys, you don't lock out the good guys. Internet security is everyone's business, and we hope that Microsoft will return to the collaborative approach that has served customers well in the past."