The simple but true way to know the CPU temperature – show the right information in the BIOS. To enter the BIOS, when you turn on the computer hold down the DELETE key. A window will appear with tabs where you need to find the system partition. Motherboard manufacturers can label it, but you should focus on the word "SYSTEM". In this section you obviously will see a line with the temperature readings of the processor. Remember, to navigate in the BIOS you can only use arrow keys because the mouse will not work.
Another option is to use one of the programs, which allows directly from the Windows observe and even regulate the CPU temperature, fan speed, etc. To such programs include SpeedFan, Core Temp, Everest and NextSensor other. Installing one of these, you will receive information about the observations of your system. Unfortunately, not all such programs provide accurate information and experts advise to focus on the readings the BIOS.