Check in BIOS to see if it is present there
If not the open the case and check connections by unplugging and
reseating them
Also reset defaults
If it is then Check Safe Mode
If it is there try removing it and the Secondary IDE Channel
If the drive is not there just remove the IDE channel
It may be that one of them has gone bad if it is not finding it in
BIOS
You can also try booting to a 98 start up disk and try loading CDROM
support to see if it will detect outside of windows