Connect the GSM module to your PC, via USB. Install USB driver, if needed [USB drivers are available in downloads section].
Start the modem having the SIM inserted into the SIM slot.
Open your favorite terminal utility [we use Terra Term]. Open the USB serial port, selecting 115200bps.
Proceeed with following AT exchange [we assume the PIN CODE is "0000", replace with your SIM card PIN code!!!]:
+CPIN: SIM PIN
* the AT COMMAND is represented in RED
* your MODEM RESPONCE is represented in underlined GREEN