EDIT: new hassle free method w/o python here
For an easy maintainable Arduino-esp8266-ide I would do something like:
a) download:
recent Arduino-ide as .zip version (https://www.arduino.cc/en/Main/Software)
esp8266 arduino core as .zip (https://github.com/esp8266/Arduino/archive/master.zip)
esp32 arduino core as .zip (https://github.com/espressif/arduino-es ... master.zip)
and install python 2.7 (https://www.python.org/downloads/windows/)
b) unpack Arduino to suitable place (e.g. d:\, keep the version info if you like to have several versions)
c) create an empty directory "portable" in this directory
d) create directory "espressif" under "hardware"
e) unpack both core .zip to this directory (and rename to esp8266, esp32 if prefered)
f) in subdir "tool" of "esp8266" core execute "get.py", in subdir "tool" of "esp32" core execute "get.exe"
g) start arduino, you should now be able to see Esp8266/Esp32 devices under tools/boards
If later you want to update to newer .git version, just download the .zip again and copy its content to the existing directory.
this gives you the freedom of the location of your Arduino-ide, simplifies backups (all in one dir) and parallel versions, keeps your settings, all sketches and additional libs in one place (portable\sketchbook)