My Dell Dimension 9100 is only 8 months old. The CD/DVDW drive it came with had been working fine, but suddenly the computer does not recognize it. I had made no changes prior to this problem. In Device Manager, it lists the drive as TSSTcorp CD/DVDW TS-H552U with a yellow exclamation point. Dell Support talked me through a bunch of fixes to try, and it finally DID get recognized, but a day later it was not recognized again. Suggestions greatly appreciated.

Start run regedit Browse to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318} In the right side delete UpperFilters and LowerFilters. Restart the PC. Your CD-ROM should now be working again. If you have CD recording software you may need to reinstall it for recording to work.

Here's the reference for John's suggestion: http://support.microsoft.com/default.aspx?scid=kb;en-us;Q314060 Do yourself a favor BACKUP!!!

Thanks to both of you! I'll try it later tonight and let you know if it works. Steve

New twist. I tried to edit the registry as suggested, but I got the message: "Registry editing has been disabled by the administrator". Well, I AM the administrator, and I have not disabled the registry. I suspect that I may have installed/uninstalled something that is redirecting regedit to give this error message. So now I need to know: how do I ENABLE the regedit?? (BTW: When I ran diagnostics on the CD/DVD drive from the Root Menu, all seems to be working fine with the drive.)

Make sure you are logged on in the administrator account.

I am listed as an Administrator on my user account (as are my teen son and teen daughter on their user accounts). I changed their accounts to "limited", leaving only me as Administrator, shut the computer down and powered up again, but still get the error message. Also, when I right-click My Computer, and then Manage, I do not find "Local Users and Groups". Could this be part of the problem?