Check the CD/DVD cure at:
beware it may not be your 100% solution but its a good place to start. Also, the drive itself can be at fault if too old or used alot. If this problem seemed to happened after a recent s/w install or update, use the system restore to go back to a prior date when working well. Check mtrbd. bios for updates that effect the buss, but only use if directly mentioned, a bios update is a serious consideration. Look for your OS as well in any update from the drive maker support website, related issues.
good luck -----Willy
I have a PC running XP professional with a Plextor 708a DVD drive. When I start my computer, the drive is fine and I can access my CDs and DVDs. After a few minutes, however, it stops being read and the drive itself disappears from "My Computer". I don't know what to do, help!!