Confused- Hard Drive selection.

[Jim]

FC12-X86_64/KDE

Installing FC12 on a friend's HP Pavilion Slimeline s7700n , the BIOS on 
this computer shows the Primary, Master is a pata CDROM and the Hard 
Drive is at
Secondary , Master a sata hard drive.

Gparted see this drive as /dev/sda and Fdisk see it as /dev/sde and
grub-install /dev/sde puts the boot loader on /dev/sde .

And I'm totally Confused,  how can this hard drive be at /dev/sde.
the hard drive also has Windows 7 as /dev/sda . Can someone explain how 
all this is working.