Yesterday, after a failed shutdown of Windows Vista (eg. it sat there for a couple hours pretending to shut down and I had to pull the battery out of the laptop to cut power to it) I noticed that the sound and network icons had gone missing from the system tray (now called the Notification Area for one reason or another), and what was worse, the options to re-enable them were greyed out.
The solution was relatively simple, but Google doesn’t appear to have picked up a solution for it yet so I’m going to write one here. This solution worked for me, and is actually a modification of a solution to a slightly different problem under Windows XP. I can’t guarantee that it will work for you, and I strongly recommend creating a system restore point before attempting the following fix.
Firstly, if you haven’t checked if you can re-enable the missing system tray icons, right click on a blank space on your taskbar and click “Properties”. Click on the Notification Area tab. If you can tick the checkboxes next to the missing icons, do so and then click the OK button. Otherwise, keep reading.
Click on the Windows icon.
Type “regedit” without the quotes and press enter.
Windows will probably ask for your permission to open Regedit. Click “Continue”.
Press CTRL + F
Type “iconstreams” and click OK
You should see a screen with two registry keys titled “IconStreams” and “PastIconStreams”. Delete both of them and press F3 (which will perform the search again).
Continue deleting the “IconStreams” and “PastIconStreams” keys until you receive the message “Finished searching the registry”.
Close the Registry Editor and restart your computer.
When the computer restarts, the icons will still be missing, however you should now be able to enable them by right clicking on the taskbar, clicking on Properties and then enable them from the Notification Area tab. If you have multiple user accounts on your computer you may need to enable icons in the other accounts as well.