If the CD drive is listed as PATA, that makes it an IDE/ATAPI drive, not an SATA Drive. This makes sense, as the GX280 specs indicate that all of the versions had an IDE (PATA) interface, as well as one or 2 SATA controllers. Also, the PATA (IDE) interface is easily fast enough for most CD/DVD use.
This means that the CD drive would have a 40 (or 80pin, for UDMA drives, unlikely for the CD drive) conductor ribbon cable connecting it to the IDE interface on the motherboard, and a 4 pin molex power connector from the power supply. The drive should have jumpers indicating it is the master drive, assuming it's the only drive connected to the cable (there can be a max of 2 on that 40 pin cable). The jumpers MAY be set for cable select, but I would set it as master and use the end connectors of the cable anyway.
Obviously the BIOS sees the drive, or it wouldn't be listed. If, with the power on, you put a CD in the drive, does it do anything? It should spin up the disc and the light should flash some while it reads and IDs the CD. If it does not, then the drive is either dead, or has no power. In that case, as I suggested separately, disconnect it completely, and make sure it is no longer in the boot order.
If it does try to read the disc, remove and re-install both cables both at the drive end and to the motherboard. Be sure that the red line on the cable is on the side for pin 1 (hard to miss, the cable should be keyed, but worth checking!) And again, move the drive to the bottom of the boot order list, just to be sure and see what, if any, error message you get now.
If the drive is/was NOT listed first (or at least, ahead of the HD) already, there may be issues with the HD. In this case, assuming you have the means to do so, download the latest copy of the Ubuntu Live CD, burn it to a CD, put the CD-drive first in the boot order, and try to boot it. If it works, you can use the Linux disk partition utility (normally gparted) to try to see what's up with the hard drives. Gparted will create NTFS partitions for Windows, but I wouldn't bother. You'll be better off to do that with a valid Windows install disk. However, you would be able to see what the OS can tell you about the drives.
WOW, long-winded SOB, aren't I? At any rate, with the error message you have reported, you have to try to narrow down the possibilities. Eliminating the CD drive, and possibly the hard drives, would be a great start. Besides, although it will be deadly slow booting and running from the CD, Ubuntu booting would pretty much gaurantee that you can get Windows to work again on the hardware.
