Fix for When Clock, Volume, Power or Network Icons are Missing in Vista
So you notice you are missing icons in the System Tray, like the clock or volume icons, and then you realize that you simply can’t enable them because the checkboxes are grayed out. So what do you do?
Fix for Notification Icons are Missing and Checkboxes are Grayed Out
You can solve all of these problems by looking in two separate places in the registry, and then deleting a bunch of keys in each location. We’ll detail all of the keys here, but you can skip down a bit for a downloadable registry hack file.
Open up regedit.exe through the start menu search or run box, and then browse down to the following key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer
If you see any of the following key names in the right-hand pane, delete them:
* NoTrayItemsDisplay
* HideClock
* HideSCAPower
* HideSCAVolume
* NoAutoTrayNotify
* HideSCANetwork
After deleting the values in that pane, browse to the following key and then repeat the process:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\
Explorer
Source: My Friends… Pc Tips for Khmer….