RegDeleteKey因ERROR_ACCESS_DENIED失败

Question

Windows Mobile:
As the final step of unloading a driver, I am trying to delete the registry subkey (HKLM\\Drivers\\BuiltIn\\XYZ) using RegDeleteKey API and it fails returning ERROR_ACCESS_DENIED code.

Below are the steps I followed:
1. FindFirstDevice
2. Stored the key and needed values for later use in case I need to reload the driver (Used RegOpenKeyEx and RegQueryValueEx APIs)
3. DeactivateDevice
4. RegCloseKey
5. RegDeleteKey


Steps 1 thru 4 work pretty fine, however, step 5 fails. Please suggest.

Answer 1

The reasons could be

• Make sure you deleted each of the contained value pairs

• You maybe trying to delete key that are not permitted to be deleted by anyone. Try changing to another key which you are able to delete for sure, and then test the code again.

• You might forget to close the handle to this key (HKLM\\szSubKey) elsewhere. You may create a new application and test the above code there.

• If it works fine in third case, the key might be used by the system or another process so you cannot delete it.

Answer 2

Just to update on this, I used bus IOCTL's to deactivate the device and re-activate it later when I am done with the intermediate actions that I had to perform. This way I didn't have to worry about dealing with registry deletion. This is pretty neat and safe. No messing up with the driver on the device, which might lead to a bad state of the system if something goes wrong while the driver was unloaded. Here is a very good article on How WinCE bus drivers work .