fixes #754 CMake may not find InitializeConditionVariable
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8f10ba8..dc17e36 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -108,6 +108,10 @@
set (NN_HAVE_WINSOCK 1)
add_definitions (-DNN_HAVE_WINDOWS)
add_definitions (-D_CRT_SECURE_NO_WARNINGS)
+
+ # Target Windows Vista and later
+ add_definitions (-D_WIN32_WINNT=0x0600)
+ list (APPEND CMAKE_REQUIRED_DEFINITIONS -D_WIN32_WINNT=0x0600)
elseif (CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
add_definitions (-DNN_HAVE_FREEBSD)
elseif (CMAKE_SYSTEM_NAME MATCHES "NetBSD")