find_package() doesn't detect boost on Windows Cmake

On Windows 7 x64 I have Boost 1.58 installed to C:\SDKs\boost_1_58_0. In order to allow cMake to find all of the appropriate files, I had to add the following three system variables:

    BOOST_INCLUDEDIR    C:\SDKs\boost_1_58_0\
    BOOST_LIBRARYDIR    C:\SDKs\boost_1_58_0\lib64-msvc-12.0
    BOOST_ROOT          C:\SDKs\boost_1_58_0\boost

In addition to the BOOST_ROOT I also had to set the BOOST_LIBRARYDIR variable to succeed. In my case this was c:\Program Files\boost_1_56_0\lib64-msvc-12.0

You need to set the environment variable BOOST_ROOT to c:\boost_1_55_0 before running cmake. Also look at cmake --help-module FindBoost for more help.