How to install the screensaver on a Windows' computer?

1. Copy the SCR file in your system folder. This folder vary with Windows version:
   Windows XP/NT/2000 => C:\WINNT\SYSTEM32
   Windows 95/98/ME => C:\WINDOWS\SYSTEM
2. Right-click in the Windows Desktop background and select 'Properties'. A dialog box opens. Select the 'Screen Saver' tab:
3. Select your screensaver in the list. (it should appear in this list if you copied it in the correct folder). The screensaver appears in the Preview screen.
4. You can adjust the screensaver settings or display it fullscreen.
5. When all done, click OK

How to un-install a screensaver?
You can simply delete the SCR file or choose another screensaver (or simply 'None') in the above list.