A while ago I started having trouble with my optical drives. Both of them keep showing up in Explorer as CD/DVD drives on boot, but as soon as I put a disc in either one, it suddenly turns into a hard-drive—“local disk” is displayed in the Type column, though the File System column remains UDF/CDFS. (I though that maybe it was a permission issue on the registry key in HKLM\System\CurrentControlSet…, but I’m not so certain because of the next test.)
Here’s a screencast of My Computer; when I put in a disc, the DVD drive magically turns into a hard-disk and cannot be opened.
When I try to open a disc (of any type), I get an access denied error message. If I open an elevated command-prompt, I am able to access the files. Also, if I kill Explorer and run it from an elevated command-prompt (thus giving Explorer elevated permissions), then I can access the files from Explorer.
I’ve tried uninstalling and reinstalling the devices without success. The security dialog indicates that there are none set for the drives (no owner and no permissions). I tried setting the owner, but am only able to do so if there is a disc in it (it complains if it is empty), but the settings do not stick (if I immediately open the security dialog after setting it, it is empty again). I tried setting permissions, but that gives an error.
I’ve included a screencap-flowchart of the security dialog of one of the drives below.
I suspect that the problem is with the registry entries related to optical drives in HKLM\SYSTEM\CurrentControlSet. For example, the Properties subkey in HKLM\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318} is conspicuously absent. Worse, I cannot figure out what should be in it or import one from a backup hive because the Properties subkeys in …\Class have some sort of “super-admin” permissions—I cannot even view the permissions or owner on these! It does say however that I can change them, but I don’t know what account owns or has permissions for them (my guess would be TrustedInstaller—or something).
(Yes, I made sure that there are no upper- or lower-filters, and yes, I ran sfc. I also made sure that in the policy editor, “devices: restrict CD-ROM…” and “removable storage access” are not set.)
Does anyone know what the owner and permissions are supposed to be for optical drives and how to reset them?
Best Answer
This behavior is very puzzling, so all I can offer are some hints and more questions.
It would help to know whether the CD/DVD drive is shared. If it is, maybe unsharing can help.
Second, whether you have a CD-burning software installed, such as Nero. You might try to uninstall such software to see if this makes a difference.
Third, run gpedit.msc and check Computer Configuration / Administrative Templates / System / Removable Storage Access. Verify that "CD and DVD: Deny read access" is disabled or not configured. In effect, all the options should be not configured.
You might also try to see what happens with "sfc /scannow" as described in
How to Repair Windows 7 System Files with System File Checker.
The last resort is following How to Do a Repair Install to Fix Windows 7, which will refresh your Windows files without requiring the reinstallation of applications.
Some anti-virus scans might also be useful.