How to read CPU temperature into Arduino?
Here is a simple way to send CPU temperature reading data via serial port, under Windows.

As answered in the question Batch-file get CPU temperature in °C and set as variable, it is possible to build batch file (*.BAT) to get the readings and output to console. I took following option and built the BAT file.

wmic /namespace:\\root\wmi PATH MSAcpi_ThermalZoneTemperature get CurrentTemperature


Now, to redirect the console to serial port, use &gt; symbol. Try following and receive it in your Arduino or use serial port monitor to check (in my case it works):

mybatfile.bat &gt; COM1


Alternatively, you can use

wmic /namespace:\\root\wmi PATH MSAcpi_ThermalZoneTemperature get CurrentTemperature &gt; COM1


inside your BAT file.

Next, we have to specify the serial configuration, make it EXE file so it can run under Administrative account. I used Advanced BAT to EXE converter. In the tool, specify the commands:

@echo off
mode COM1 BAUD=38400 PARITY=n DATA=8
wmic /namespace:\\root\wmi PATH MSAcpi_ThermalZoneTemperature get CurrentTemperature &gt; COM1


Convert it to EXE using File->Build EXE...



And finally, you can create Scheduled Task to run your newly built EXE application periodically.

BTW, WMI is a powerful interface, it is possible to retrieve many other metrics and configuration data.