A. A. You can easily recreate this by running systray.exe. To ensure that you have the speaker icon every time you start windows you can place it in your startup group.
Verify that the SystemTray value name at HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run has a text string of SysTray.exe.
Alternativly start the Multimedia control panel applet (start - settings - control panel - multimedia) and check that "Show volume control on the taskbar" is checked.