If I use the Dualcore Processor then system has no problem at all . The Problem comes with the Core 2 Duo Processor Only . As i take a guideline from memory vendor they suggested that upgrade the motherboard bios , so i download the bios and try to install . The Problem is that bios update runs but when it restarts it does not flash , and last it shows Bios Update Sucsssfully . But it does not update and display does not come out . Now one can help me in this matter why it happened ?
I had a look at the CPU compatibility chart for your model of motherboard here: http://processormatch.intel.com/CompDB/SearchResult.aspx?BoardName=DG41WV and it shows that for some 2.93 GHz CPUs, certain AA revision DG41WV motherboards are required. This means that if your board isn't this revision (and you can find the AA revision information in the BIOS and on the board and its box) then they won't go together. That said, I like the idea of getting the BIOS to successfully flash first as recent BIOS revions incorporate fixes not only for improved CPU support, but also to allow improved DIMM support (2 Gbit SDRAM density). If you have a carefull read of the README.pdf file where the BIOS updates for your board are, it'll tell you how to use the updates. If your going to use the express method under Windows then you'll need to ensure all security software is turned off first or you may get the problem you've already referred to of the BIOS appearing to update but not really doing so. You could otherwise try one of the other BIOS flashing methods (following those instructions carefully). You should have an already compatible CPU and RAM in the board when you perform the BIOS update so if the Dualcore one with your memory works fine for testing purposes, leave that installed while you flash the BIOS.
When you say display does not come out - if that means the board will not display anything (at all) then you'll need to use the recovery method to update the BIOS as this is done without need of a display or user input during the process - again, instructions are on the website for how to do this.
Additionally, (according to the page on Intels website about this board), 'DG41WV only supports 4GB DDR3 memory in 2x 2GB memory configuration. DG41WV will not work with 1x 4GB memory configuration.'