WDM_INC_PATH
Use the WDM_INC_PATH macro to specify the path to the WDM header files.
If the DRIVERTYPE macro in your Sources file is set to WDM, the Build utility will use WDM_INC_PATH instead of DDK_INC_PATH.
In the Windows Driver Kit (WDK), the default value is:
WDKROOT\inc\ddk
For this default value, WDKROOT is the root installation directory of the WDK.
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Build date: 5/3/2011