Index: /trunk/src/VBox/Frontends/VirtualBox/ui/VBoxVMSettingsSystem.ui
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/ui/VBoxVMSettingsSystem.ui	(revision 24039)
+++ /trunk/src/VBox/Frontends/VirtualBox/ui/VBoxVMSettingsSystem.ui	(revision 24040)
@@ -336,5 +336,5 @@
          </property>
          <property name="whatsThis">
-          <string>When checked, activates support for Extended Firmware Interface (EFI), can be used to boot certain guest OS. Activate only if fully understand the consequences.</string>
+          <string>When checked, activates support for the Extended Firmware Interface (EFI), which is required to boot certain guest OSes. Non-EFI aware OSes will not be able to boot if activated..</string>
          </property>
          <property name="text">