When custom EAP authentication dll calls EapPeerInvokeInteractiveUI for wireless LAN 802.1x, a dialog box is displayed and a balloon is popped-up on Windows Vista machine. And the developer of the EAP authentication dll, needs to suppress dialog box and balloon.
The scenario is like - You are using custom EAP authentication dll which call EAPHost EapPeerInvokeInteractiveUI function to display a custom dialog box to the user to gather user's credentials. On Windows Vista, there is an additional dialog box displayed by system to get user consent whether they want to "Enter/select additional log on information" or "Connect to a different network" . Clicking on "Enter/select additional log on information" on the consent dialog, the actual dialog is displayed. You want to suppress this intermediate system consent dialog box and possibly balloon as well.
There is no way to suppress the dialog and balloon on Windows Vista machine, this is by design. On Windows 7, the dialog box has been eliminated by design but balloon is there when the call to EapPeerInvokeInteractiveUI will be made by EAP dll. This is true for profile based authentication and non-profile based authentication if authentication requires user input.
Windows SDK – Microsoft