I have attached the specs for your board. Unfortunately, I didn't save a copy of the board's Processor Compatibility chart, so I am going to have to go from memory. Unfortunately, I believe that this board only supported the first (Conroe) generation of the Core 2 Duo processors, which would be up through the E6700 processor. I do not believe that the E8400, which is a second (Wolfdale) generation Core 2 Duo processor, was ever supported.
After delving way back into 2011's compatibility tool (using the aptly named Wayback Machine), I have been able to determine that the DG965WH board,
- Does support the Q6600.
- Does not support the E5700.
Now, I will also say that, according to this compatibility tool, my board, the DQ965GF, does not support the Q6600, yet that is the processor that I have in it.