To: SUB MESA,
Thanks for help.
I meant I can not read any DVD at all. The DVD missing from "My Computer" list. Right now I have only 1 hard disk with 2 partition ( C: and D:) only. Usually I will have E: drive for my DVD, now it's gone.
I search on google, yahoo etc; many people experience the same problem, but the solution very varies and no certainty. By the way, I have Itune for my Iphone on this laptop and recently I just up grade to the newest version of itune 9.?.?. I check their website, they also directing to Microsoft for the solution to eliminate upper and lower register using regedit.
But I fixed it and only one time and then the E: drive or DVD drive is gone again.