I would say the issue is most likely that your SATA drivers aren't loaded.
Whilst installing, there will be a brief prompt asking you to hit F6 if you want to install RAID drivers.
You need to hit F6, and insert a floppy disk with the drivers on it. If you haven't got one, you'll need to refer to the motherboard manual in order to find out how to make one.
Before you try this, you might want to give Memtest a shot -
http://www.memtest.org/#downisoDownload it, unzip it, and burn the ISO to a CD. Then boot from the CD and have it test your memory for a long time, preferably overnight. if no errors are shown, your RAM isn't the issue.
I do think it's the SATA drivers though, that's usually what causes this issue.