Missing System Icons solved
The missing system tray icons mystery is solved. It was corrupt "IconStreams" and "PastIconStreams" cache.
Navigate to the key "HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\CurrentVersion \TrayNotify"
There should be several entries (I'm assuming you know how to edit the registry). As a safeguard, right-click the TrayNotify entry and select export, and save the registry entries should something go wrong. If you have a backup, you can always import the settings again.
Delete the values "IconStreams" and "PastIconsStream" entries in the right panel.
Now, you can either shutdown and restart your system and the icons should rebuild, or you can launch task manager, shutdown explorer.exe, restart explorer.exe, and they will be recreated without shutting down.
The quickest way to get to task manager in Windows Vista is to right-click in the bottom toolbar, right-click, and select task manager. Find explorer.exe, highlight it, click end process.
Now WAIT. Before closing that windows (since you can't navigate well now with explorer shut down), click the Applications tab, and down in the lower right corner, click New Task...
In the box that opens, type explorer.exe, then OK. Explorer should restart and all of the system tray icons should be there. As you can see, both of the icons are now there:
And as you can see, the options are no longer grayed out:
