|Microsoft DirectX 9.0|
Unlike previous versions of Microsoft?Windows? Windows XP allows multiple users to log on simultaneously. Each user account has its own running applications and settings. The current user does not need to log off in order to switch to a new user. The fast user switching feature of Windows XP basically disconnects the current user account and brings the newly connected user account to the foreground. The disconnected user's applications and desktop settings remain loaded and running in the background.
While fast user switching offers a new level of convenience for users, it must be handled properly. Applications that use shared resources need to ensure they don't interfere with the currently connected application. Microsoft DirectPlay?Voice applications use shared resources and have the potential to cause problems when users switch. In particular, voice transmissions from the disconnected DirectPlay Voice application could still be audible, interfering with the current user's applications. To prevent such problems, DirectPlay Voice automatically mutes voice transmissions when a user's account is disconnected and unmutes transmissions when the account is connected again. This feature relieves your DirectPlay Voice application of the need to detect and handle a user switch.