Windows Vista VISTA 64 and BCOD crash dump

I just recently put togther a new computer for my daughter and after my warning of VISTA problems, she insisted she wanted that anyway. The MB, HDD, memory, processor and video adaptor are all VISTA compatable. WD HDD, Asus MB, MSI video card, AMD quad core 2.6 and 4 gigs of Corsair PC6400 memory. This is Vista 64 bit and seemed to run good after I installed a seperate video card. (NVIDIA 8500) Prior to this installation, I used the onboard vga. Also Nvidia. I couldn't even make a display adjustment without a BCOD right away. After I installed seperate video card, problem worked very stable for a while. Now BCODs are back a few or more times a day. I ran the built-in memory checker. Everything OK. I removed one memory stick leaving 2 gigs for testing. Am I on the right track? Google finds thousands of sites pointing to VISTA and BCOD. Is the system so sensitive that any glitch in hardware would cause these problems?