I tried installing Fabric in my Windows 7 64-bit machine and all I got was this lousy error message:
building 'Crypto.Random.OSRNG.winrandom' extension
warning: GMP or MPIR library not found; Not building Crypto.PublicKey._fastmath.
error: Unable to find vcvarsall.bat
None of the answers in this similar question error: Unable to find vcvarsall.bat worked for me. What to do?