An anonymous reader writes:
While Microsoft was telling security companies that there was no way it could change its PatchGuard kernel protection to make their products work, it had already quietly released a hotfix that changed PatchGuard to make Virtual Server 2005 work with AMD's hardware. This from Skywing, who has written a pretty interesting paper on subverting PatchGuard. Skywing says, "despite Microsoft's statements that no exceptions would be made for PatchGuard, they have had to make adjustments at least once for their own code to run on PatchGuard. The conspiracy theorists among you might wonder whether Microsoft would be so gracious as to make such exemptions for legitimate uses of techniques blocked by PatchGuard for third party software with similar needs as Virtual Server 2005 R2 SP1, given their pointed statements to the contrary."