It does not detect the hardware anymore? If it does not find anything at all, look for any 'unknown device' like I described above. If there is no unknown indicated, then power down the computer, open up the side, and then unplug and replug in the cables that go to your CD/DVD drive. Sometimes its a loose connection. Sometimes it truly is a dead drive. Before doing this, can you open and close the tray? If you can, then power is getting there fine. If it does not open, then could really be dead. (from your previous post, seems that power is OK) If power is OK (drive can open and close), typically the HPs have multiple sata ports on the motherboard. See if there is a unused one on the motherboard, and unplug the sata cable from the motherboard where the CD drive is currently connected, and connect to a different port on the motherboard. Be sure to 'press' the cables at the back of the drive to make sure nothing is loose. After you do this, power up and see what happens. I will be on for a bit, and will help, if you want it. I will let you guess what one of my jobs used to be, and still is .
No they are backwards compatible. 3 works with 2, 2 works with 3. You just will not notice the faster transfer rate of usb 3.
