Corrected "X-Windows" to "X-Window"

Fix #3209

Signed-off-by: Sandro Bonazzola <sandro.bonazzola@gmail.com>

Author: sandrobonazzola

source/documentation/virtual_machine_management_guide/chap-Administrative_Tasks.adoc

@@ -184,7 +184,7 @@ include::topics/Enabling_SAP_monitoring_for_a_virtual_machine_from_the_Administr
 
 SPICE is a remote display protocol designed for virtual environments, which enables you to view a virtualized desktop or server. SPICE delivers a high quality user experience, keeps CPU consumption low, and supports high quality video streaming.
 
-Using SPICE on a Linux machine significantly improves the movement of the mouse cursor on the console of the virtual machine. To use SPICE, the X-Windows system requires additional QXL drivers. The QXL drivers are provided with {enterprise-linux} 5.4 and later. Earlier versions are not supported. Installing SPICE on a virtual machine running {enterprise-linux} significantly improves the performance of the graphical user interface.
+Using SPICE on a Linux machine significantly improves the movement of the mouse cursor on the console of the virtual machine. To use SPICE, the X-Window system requires additional QXL drivers. The QXL drivers are provided with {enterprise-linux} 5.4 and later. Earlier versions are not supported. Installing SPICE on a virtual machine running {enterprise-linux} significantly improves the performance of the graphical user interface.
 
 [NOTE]
 ====

source/documentation/virtual_machine_management_guide/topics/Configuring_a_virtual_machines_tablet_and_mouse_to_use_SPICE.adoc

@@ -48,4 +48,4 @@ Option "CorePointer" "true"
 EndSection
 ----
 
-. Log out and log back into the virtual machine to restart X-Windows.
+. Log out and log back into the virtual machine to restart X-Window.

source/documentation/virtual_machine_management_guide/topics/Configuring_qxl_drivers_on_virtual_machines.adoc

@@ -28,7 +28,7 @@ You can configure QXL drivers using either a graphical interface or the command
 . Click the *Hardware* tab.
 . Click *Video Cards Configure*.
 . Select *qxl* and click btn:[OK].
-. Restart X-Windows by logging out of the virtual machine and logging back in.
+. Restart X-Window by logging out of the virtual machine and logging back in.