Currently, we use Microsoft Platform SDK version 6.0a to build JDK7. However, this SDK misses many important features provided in the recent MS operating systems. For example, AWT/Swing teams need headers/libs for multi-touch input available in Windows 7.
One of the option could be to copy some of the headers into JDK source tree. We used this approach for JDK5/6, but it's prone to errors and require additional engineering support. JDK7 is built another way: in built-time we use the highest available Windows version (at the current moment: Windows 7, which correspond to _WIN32_WINNT=0x0601), use delayed dll loading and check for the particular Windows version in runtime. This approach is more flexible and recommended by Microsoft.
This CR is a part of general strategy to use recent MS development tools to build JDK.