==== MouDeRegister ====

**Bindings**: [[dereg#C bindings|C]], [[dereg#MASM bindings|MASM]]

This call deregisters a mouse subsystem previously registered within a session. 

//MouDeRegister// ( ) 

//rc// (**USHORT**) - return 
Return code descriptions are: 

^0 ^NO_ERROR ^
|385 |ERROR_MOUSE_NO_DEVICE |
|416 |ERROR_MOUSE_DEREGISTER |
|466 |ERROR_MOU_DETACHED |
|505 |ERROR_MOU_EXTENDED_SG |

**Remarks**

Processes issuing [[en:ibm:prcp:mou:dereg|MouDeRegister]] calls must conform to the following rules: 

  * The process that issued the [[en:ibm:prcp:mou:register|MouRegister]] must release the session (by a [[en:ibm:prcp:mou:dereg|MouDeRegister]]) from the registered subsystem before another **PID** may issue [[en:ibm:prcp:mou:register|MouRegister]]. 

  * The process that issued the [[en:ibm:prcp:mou:register|MouRegister]] is the only process that may issue [[en:ibm:prcp:mou:dereg|MouDeRegister]] against the currently registered subsystem. 

  * After the owning process has released the subsystem with a [[en:ibm:prcp:mou:dereg|MouDeRegister]], any other process in the session may issue a [[en:ibm:prcp:mou:register|MouRegister]] and therefore modify the mouse support for the entire session. 

=== C bindings ===

<code c>
#define INCL_MOU

USHORT  rc = MouDeRegister(VOID);

USHORT           rc;            /* return code */
</code>

=== MASM bindings ===

<code asm>
EXTRN  MouDeRegister:FAR
INCL_MOU            EQU 1

CALL   MouDeRegister

Returns WORD
</code>