I installed a trial version of a 3D aquarium (Visa enabled they say). I had
to type in a password to start it. Decided not to buy it and uninstalled
through the control panel. Now the Vista screen saver will not start when it
is supposed to. I have checked the power options and neither the screen nor
the hard disk are set to turn off; it is still on the setup of Balanced.
I have been told that the registry may have lost the Vista screensaver
command.
How do I get this back without doing a reinstall?

Chappie