[TippeX]

1. check if the dvd is reported in the bios during the bootup post operation, if not u have cabling/power issues.. if so proceed to step 2
2. load windows in safe mode, see if the drive appears in the my computer, if so a restart might simply fix it, if not proceed to step 3
3. in the system configuration / device manager see if any devices are detected there and/or are disabled, if the dvd drive is one of them try reenabling it
4. if the above was not successful, try this (entirely at your own risk)
remove the ide driver, and the cdrom etc.. from the device manager, reboot and see if windows redetects them, sometimes you have to remove the controller from device manager to force windows to do a complete redetect, it has happened to me a few times, but again this is entirely at your own risk, it should be safe as windows should redetect the items again, but each pc is different thus there is a potential your windows might not start up again... good luck