With this described command, you can easily examine the current and maximum clock speed of your Windows 7 computer’s CPU clock speed.
Open an elevated Command Prompt window and run this WMIC command in Windows 7 to check the CPU current clock speed and expected clock speed repeatedly at 5 second interval:
wmic cpu get CurrentClockSpeed,MaxClockSpeed /every:5
You will get like this:
If there is disparity, send your computer to be checked by an expert: the cooling system of CPU might be faulty.