This problem was found by code inspection and there's no testcase currently to show any failure. In general, the KEY_WRITE flag shouldn't be used if opening a registry key for reading only. On Vista, writing a registry key under the HKLM branch requires a proecess with high integrity. So a process with integrity below the high level will fail when trying to open a registry key under the HKLM branch with KEY_WRITE flag on Vista.

The GetLatestJavaKey() function in RegCommon.cpp has this problem.
All the registry keys in that method should be opened with the KEY_READ flag only.

Please also check other registry related code in regutils and regutilsmsi for this kind of issue.