# Close > [HTML Version](close_mx138.htm) **xcall MIAMEX, MX\_REGISTRY, REGOP\_CLOSE, hkey, status** This function is used to close a handle previously opened. _hkey_ \[in\] must be set to the handle of the key to close (as returned in HKEY2 by the open or create operations). _status _(F6) \[out\] 0 for success, else error.