Deletes a subkey and all its descendants
#include <WinAPIReg.au3>
_WinAPI_RegDeleteTree ( $hKey [, $sSubKey = ''] )
| $hKey | Handle to an open registry key, or any of the following predefined keys: $HKEY_CLASSES_ROOT $HKEY_CURRENT_CONFIG $HKEY_CURRENT_USER $HKEY_LOCAL_MACHINE $HKEY_PERFORMANCE_DATA $HKEY_USERS |
| $sSubKey | [optional] The name of the key to delete. |
| Success: | 1. |
| Failure: | 0 and sets the @error flag to non-zero, @extended flag may contain the system error code. |
Search SHDeleteKey in MSDN Library.