Once the installation is complete, find the location of the cabal folder by opening command prompt and typing in "cabal user-config init"
Copy the path given, without the "\cabal\config" at the end, and paste it in explorer
extra-include-dirs: C:\Program Files\Haskell Platform\8.2.2\mingw\include
You do not have to replace the lines that contain the left side tags (ie. the given extra-prog-path does not have to overwrite the existing extra-prog-path in the config file).