Get correct board information for Arduino:

Go to prefrences --> Additional board manager URLs, copy and paste: http://arduino.esp8266.com/stable/package_esp8266com_index.json
press Ok.

Go to Tools --> Boards --> Board Manager
Search ESP and Install. 

Go to TOols --> Boards --> Sparkfun ESP8266 Thing Dev

Board Settings:  
80 MHz
Port: COM5 or COM6 usually


http://www.ftdichip.com/Drivers/VCP.htm