Just open the file you just downloaded with Explorer, open it and RT will install it automatically then do the following:

Go to Monitoring -> Setup -> Plugins and tick C2DTemp.dll plugin. CPU temperatures (for both cores) will appear on RT's graphs after that.

Should you not be able to figure that our then the Author (Igor Levicki) has written a full step-by-step guide in this thread.

사용 방법은 다음과 같습니다.

Here are the instructions on how to install C2DTemp plugin:

1. Double-click on C2DTemp.rtu in Windows Explorer and click Ok on the following dialog



2. Start RivaTuner



3. On the Main tab click on the first Customize... button and then on the fifth icon from the popup menu (Hardware Monitoring)



4. Click on the Setup button in the lower right corner



5. Click on the Plugins button in the lower left corner



6. Place a checkmark next to the C2DTemp.dll and click Ok



7. Place a checkmark next to the newly available data sources and click Ok



8. That's it. Now your hardware monitor should look something like this:



I am waiting for your feedback.