IDE 1.7.10 has no Borad Manager listed

Hello sir! i am having problem to install Esp8266 board manager on portable Arduino Ide1.6.5-r5, i have tried

many methods such as to download from board manager by adding portable folder in Arduino installation

folder,also add additional board manager i-e

URL"http://arduino.esp8266.com/stable/package_esp8266com_index.json"during installation through board

manager unfortunately i get an error "error dowloading

https://github.com/esp8266/Arduino/releases/download/2.3.0/esp8266-2.3.0.zip" beside that i manually

downloaded the package but don't know the exact directory for the package Thanks in advance!