Kindly give the solution for this issue.
One of the few things you've not tried - a different PSU. You should also ensure all of the latest drivers for your motherboard are correctly installed. I'm also assuming your unspecified 'Dual core' CPU is listed as compatible with the board (even though it may pluig into the board, that does not guarantee compatibility - especially with newer CPUs on older motherboards or vice versa). You can check CPU compatibility on this motherboards support section of the Intel website.
I've experienced such issues in the past with another motherboard after having changed the PSU, with the original PSU, there wasn't a problem. Does whether the PC is warm (has been running for a while) make any difference to this behaviour - it did for me. You may have to trial different PSUs as even though a PSU may be to spec, these things can be temperamental so make sure your supplier understands this (or is willing to test the PSU they install on the PC for you).
What Ram are you using ?? DDR3-1333-10600 or 10666 ?