When you connect the WeMOS D1 mini board for the first time on your Windows computer through a USB cable, it might be the case to install a USB-to-SERIAL driver. The board has a USB-to-SERIAL converter (CH340 chip). The driver is
WeMos D1 mini ESP8266
The D1 mini is a mini wifi board based on ESP-8266EX from WeMos.cc.
ESP8266 NodeMCU pins GPIO
If you are using a NodeMCU firmware on you ESP take note on the GPIO table mapping. All access is based on the I/O index number on the NodeMCU dev kits, not the internal GPIO pin.
ESP8266 NodeMCU board from LoLin
This is a ESP8266 NodeMCU board from LoLin.