How to remove regestry?

I just got a new tricks for Vista as well as XP users from and it will show you how you can disable the system tray from your computer with a simple registry hack..!

disabling the system tray doesn't actually prevent system tray applications from running, it will only hide them. You may still disable or enable any applications that aren't needed.
Follow the steps to do this :
Open up regedit.exe through the start menu search or run box, and then navigate down to the following key (Create if it doesn't exist):

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer

Create a new 32-bit DWORD value in the right hand pane with these values:

Name: NoTrayItemsDisplay
Value: 1
just reboot your system and you are done. If you don't like the process or unfortunately you saw that your system tray has vanished, then you will get it back by reversing the above process by setting the value to "0"
There may be same registry key exist in more than one location, so if you are trying to reverse this hack, you should search the registry for NoTrayItemsDisplay.