Do the following (Works for both Win 7 and Vista):
1. Right Click on an empty spot on the taskbar or Click the Start ORB - in the search line type Taskbar.
2. From the right click of the taskbar select PROPERTIES or from the programs list right click Taskbar and Startmenu.
3. From the list that appears select the Notification Area tab
4. Under the System Icons place a check mark in the box to the left of VOLUME
5. Click Apply
6. Click OK