You need to be root to run fdisk.
Try one of the live distros and go to a terminal window and type:
su fdisk -l (lowercase L)
Enter the root password if required and post the result.
Most distros will see sata drives.
Make sure your bios for the hdd mode is set to sata and not ide.
It seems to be working now. Thereś something either wrong with the hard drive or the connection, but it seems to be intermittent. I was able to install Ubuntu 8.04.1 Server on the computer and succesfully installed the desktop. I switched the SATA input the hard drive was on, and so far so good