Question My Cpu is using 2.39 ghz.Please help

[Tamim4321]

My specs are:
GPU:NVidia gt 730gddr5 (Gigabyte rev 2.0)
CPU:Core 2 Duo e8400 3.00ghz
Ram:4GB (2x2)
MotherboardDR2
OS:Windows 7 64bit (service pack 1)

I am facing serious problems.My Core 2 Duo e8400 Running at the speed of 2.39GHZ.I have disabled Speedstep but it won't effect.
In the BIOS it says my CPU is running at 3.00GHZ on 9 ratio.When my windows bootup it reads CPU 3.00ghz but in CPUz it shows that it's using 2.39GHz.I have stressed my CPU but nothing matters.I have also checked Power Settings.Everything is set to 100%.
Note:When I enable Speedstep.Windows reads 3.00GHz.But when I disable Speedstep,Windows reads 2.39 GHz.

What is the Fix??Will reinstalling Windows fix this Problem??

 

[Lutfij]

You may want to first list your ram's specs as well as the make and model of your PSU(and it's age). Then try and see if you have any BIOS updates pending. Where did you source the installer for Windows 7 from?