XP will not boot up from SATA hard drive

I just finished building a new system (the specs of which are listed below)
and after spending hours and hours attempting to install Windows XP
Professional to the SATA hard drive, I finally figured out how to do it. I
was having major problems getting XP to install to the SATA drive. It would
appear to copy the files there during the pre-install, but when it rebooted,
I would either get an error message (disk read error occurred) or the system
would just sit there doing nothing. I tried installing the SATA drivers via
floppy disk and F6 during the pre-install and that did not change things.
Finally, someone suggested disconnecting my secondary PATA hard drive and I
did so, along with my Zip drive which was on the same IDE channel. XP
installed successfully onto the SATA drive.

Now to the current problem. Once I went in and reconnected the PATA hard
drive and the Zip drive, XP once again will not load. The SATA drive is set
as the first boot device in the BIOS, but for some reason it just will not
load as long as the PATA drive and the Zip are connected. I also tried
disconnecting just the PATA hard drive and leaving the Zip and still no go. I
just keep getting the error message "A disk read error occurred. Press
ctrl+alt+del to restart." I am totally stumped as to what else to do. Any
suggestions would be greatly appreciated!

Thanks in advance,

Motherboard: Gigabyte GA-M55SLI-S4 (rev. 2.0) with F8 BIOS
Video Card: EVGA GeForce 7600GT 256 MB
RAM: 2 GB, 667 Mhz (2 X 1 GB sticks)
Primary Hard Drive: Seagate 300GB SATA II drive
Secondary Hard Drive: Maxtor 45 GB IDE
DVD Drives: Lite-On 20X dual-format DVD burner
NEC 16X dual-format DVD burner
Other drives: Zip 250 drive
Floppy drive