add_subdirectory error in CMake when installing Google Test

Question

When I run the cmake .. command while installing Google Test, the following error occurs:

CMake Error at CMakeLists.txt:33 (add_subdirectory):  
 add_subdirectory given source "googlemock" which is not an existing   
 directory.

-- Configuring incomplete, errors occurred!

How do I solve this? These are the commands I was running beforehand:

1. When I first used the cmake .. command, it failed with 'nmake' '-?' as the output
2. Then I tried running cmake . -G "MinGW Makefiles", and received the add-subdirectory error above
3. After that, when I tried the cmake .. command again, the same error occurs

Screenshots of the errors: