I just replaced a server running Windows Server 2003 Standard Edition with an Intel server using the new S5500BC system board and struggled-through a major conundrum. Everything worked just fine with 2 GB of memory, but as soon as I slapped the second DIMM into place, though BIOS would correctly report 4 GB of memory, Windows would blue screen every time. It would not even boot into Safe Mode. This held true despite having updated the BIOS and all firmware drivers and getting the OS current with all updates.
I was at a loss, even spending time through two lengthy telephone sessions with Intel support staff that left us both scratching our heads without any resolution. I assumed that I had a bad DIMM as I could get the system to boot with one DIMM (have 2 - 2 GB DIMMS) in either the A1 or B1 slot. I got a replacement set (all Intel Certified stuff) but no change.
I stumbed upon a clever work around on the Microsoft "Setup" forum from another that had suffered from the problem. The solution is to disable the "Intel System Management BIOS Driver" in Device Manager. I'd prefer not to live this way and wonder if there is an updated BIOS driver that fixes the problem? I was very careful to download and install all updates from the Intel site and am fully current across the board. In the meantime the server is fully functional but I'd prefer to have a solution prior to putting the server into production next week.
I'd heard of some interference with the Microsoft IPMI driver. I see there's a BIOS that came out a month or so later - http://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&ProdId=3076&DwnldID=17892&lang=eng. You can also disable the IPMI driver in Device Manager (if you can get past the blue screen).