Building ArduCopter on Windows 7

Continuing the discussion from Building APMRover on Windows:
@mroberts, @rmackay9

Hi All
I am trying to build ArduCopter on Windows 7 using PX4Toolchain with Eclipse or Make
I got the same error as in the link: Building APMRover on Windows

make[1]: Entering directory `/c/Users/eedison/Documents/GitHub/PX4Firmware’ %% Configuring NuttX for px4fmu-v1 include/arch already exists but is not a symbolic link make[2]: *** [clean_context] Error 1 make[1]: ***

Anybody have resolved this issue?
Any help is appreciated