key

A string whose value is the key in the
system registry you want to delete or whose value you want to delete.

To uniquely identify a key, specify the list of parent keys
above it in the hierarchy, starting with the root key. The keys
in the list are separated by backslashes.

valuename

A string containing the name of a value
in the registry. If the specified key does not have a subkey, specifying
an empty string deletes the key and its named values.