Have you tried disconnecting the DVD drive (while the computer is powered down, of course) and the booting it up...and then shutting down and reconnecting it?

You can then try to reinstall and reconnect the drive to see if it can be revived, but most likely it will just have to be replaced.

The system slowdown could be a result of a powersupply problem, and could also be caused by NIS 2007. If you will check the Privacy and Security discussions, you will note a definite lack of support in favor of NIS or McAfee for that matter. Slowing down a system is one of the complaints. If the power supply is definitely going bad, it could also cause the DVD problems, either by losing power on one of the "trunks" of power connectors, or a surge damaging the DVD drive.

Please post back with system specifics such as HD size, CPU brand and model, or PC make and model. Then also list the power supply ratings (this can be found on the label on the side of the PSU).

1. Software/drivers - since it had been working and stopped suddenly, this did not seem likely. Also the fact that it did not show up in the device manager in any form also threw considerable doubt on this possibility.

2. Mechanical - in this situation the drive would have had to give some indications that the gears on the tray were going out or that the read mechanism would have caused trouble.

3. Electrical - this was the most likely cause, because if the signal cable were not connected, the drive tray would still have functioned, but would not read/write the disk. If the power cable were not supplying power, then the drive would have been totally inert, with no indication in device manager and the tray would not function.

The most likely cause would be that in the assembly of the machine, the electrical plug did not get fully seated, but enough to make electrical contact. Over time with the vibration of the drive and machine, the plug backed out enough to break the contact. Removing the drive and then reinstalling, when the electrical connection (the large flat black plug as I believe your drive is SATA from the date of the machine) was re-inserted the problem was solved. I was also looking at the power supply because they can sometimes lose one circuit. If you look at the bundles of wires from the PSU, there are 2-3 that have device connectors on them, and if one line goes bad, everything connected on that line no longer gets power. Having upgraded and built PC's, when I press on the tray button and nothing happens, I reach around and plug in the drive.

Norton's Anti-Virus is probably OK, but stay away from NIS. When your subscription comes up for renewal, review the postings in the Privacy and Security discussion venue and save yourself some money.

Enjoy your machine, you might want to consider an anti-spyware package to protect your machine - I have good luck with Superantispyware (free) and AVG anti-spyware (also free) have good recommendations by the communities most respected member in this area SpiritWind. I am moving away from Webroot's Spysweeper on my older machines to Superantispyware.