The product guide describes memory configurations for up to 8GB (should be on the installation disk or online).
All four slots worked on my 965WH. I'd still be using it if I hadn't ended up with an extra DG45ID. The graphics slot was also damaged by another component.
I had Kingston myself long ago and it seemed fine. Single channel doesn't bother some people but you could check the scores. For more advanced tests see the recent BeHardware discussion (where channels discussed mean CPU). Those tests probably cost.
Install a matched pair of DIMMs equal in speed and size in DIMM 0 (blue) and DIMM 1
(black) of channel A. Install a DIMM equal in speed and total size of the DIMMs
installed in channel A in either DIMM 0 or DIMM 1 of channel B (see Figure 15).
Figure 15. Dual Channel Memory Configuration Example 3
All other memory configurations will result in single channel memory operation.
thanks for your helps, but I did somehow get them work, no idea what happened. But I did download the new bios and upgraded mine. Then I tried to install the 4th RAM and powered on but it was blank again. After that, I restarted and pressed F2 for bios settings and guess what, it started to show up.
A few hours after I found that I forgot to attach the DVD IDE so I attached it and it was blank. I had to press F2 again (hoping it would work) and it worked.
So, in my opinions, when I attach some new devices, the system will need to regconize them for the first run. It may work on the second run (a bit slower than before, just like when we use new equipments :D).
Anyway thanks again for your helps, curious!