About blocking access to some keys in registry of the smartphone
There are certain keys under HKLM (all of them documented in the SDK) that
you cannot write to without being a "trusted" application (signed with a
trusted root certificate). These are generally meant to prevent the phone
from installing unsafe drivers. You should contact the OEM if there are
additional keys locked (for example, I'm not aware of MS blocking HKCR at
all).
