Just so you know, for some reason when you do a clean install of Windows Server 2008 x64 on a machine with Adaptec's CERC 1.5 6-Channel SATA RAID card, Windows doesn't have drivers built in.
Easy enough, you can go get the drivers from the manufacturer website--in my case Dell. Obviously you want to use the x64 drivers because it's an x64 operating system. When you attempt to use the x64 drivers via the "Load Driver" option, because it can't detect the disks otherwise, it gives you the following helpful message:
"To continue installation, use the Load Driver option to install 32-bit and signed 64-bit drivers."
There's a little bit more to the "error" message, but ultimately what it is saying is that it doesn't like your drivers. I Googled around for a bit and found other related posts that had a slightly different problem--the infinite BSOD/reboot loop.
In my particular case I actually tried the x86 drivers out and it solved it for me. Once I get the system up all the way I'll just replace them with the x64 drivers.