CMake can't find GLEW - cmake

Question

I've read this [1], but in my case CMake says it can't find glew.
I'm on Windows and there is a FindGLEW.cmake file in my CMake modules folder, presumably put there when I installed CMake-3.6. I found GLEW on sourceforge and downloaded the zip file for Windows. I unzipped and installed in C:\Program Files\glew. When I've created my own libraries and used CMake to build and install them, this is the default location they are installed to so I am pretty confident I'm OK here.
The snippet from my CMakeLists.txt is:
find_package(GLEW REQUIRED)
include_directories(${GLEW_INCLUDE_DIRS})
link_libraries(${GLEW_LIBRARIES})
The actual error message from CMake is:
CMake Error at C:/Program Files/CMake/share/cmake-3.6/Modules/FindPackageHandleStandardArgs.cmake:148 (message):
Could NOT find GLEW (missing: GLEW_INCLUDE_DIR GLEW_LIBRARY)
Call Stack (most recent call first):
C:/Program Files/CMake/share/cmake-3.6/Modules/FindPackageHandleStandardArgs.cmake:388 (_FPHSA_FAILURE_MESSAGE)
C:/Program Files/CMake/share/cmake-3.6/Modules/FindGLEW.cmake:44 (find_package_handle_standard_args)
source/CMakeLists.txt:5 (find_package)
Is it possible the FindGLEW.cmake is broken? I've looked at a couple of other FindXXXXX.cmake files and they are like snowflakes, each one pretty unique. So it's hard for me to say with any certainty that it's following convention.
[1] Linking GLEW with CMake

Answer 1

Looking in the sources, the package is looking for GLEW in relative paths. These relative paths are searched using different prefixes, including the content of the variable CMAKE_PREFIX_PATH:
<prefix>/include for find_path which is used to find include directories.
<prefix>/lib for find_library which is used to find libraries.
Assuming C:/Program Files/glew/include and C:/Program Files/glew/lib exist, add C:/Program Files/glew to your CMAKE_PREFIX_PATH variable. Something like:
list(APPEND CMAKE_PREFIX_PATH "C:/Program Files/glew")
find_package(GLEW REQUIRED)
Note that the following lines:
include_directories(${GLEW_INCLUDE_DIRS})
link_libraries(${GLEW_LIBRARIES})
may be dropped using imported target Glew::Glew:
add_executable(foo ...)
target_link_libraries(foo Glew::Glew)