Never install anything on your computer.
That being said - you now have adware, spyware, etc on your computer.
Now - it is was a screen saver & not necessarily a program - you can search in your Windows for *.scr - but it more than likely was a program.
So you need to go to Start - Control Panel - Add / Remove Programs. See if you see that screen saver there - hopefully it is there & it will remove everything for you. Do you see new.net there? Remove that. Or what about Virtual Bouncer? Something possibly like that. Or maybe IncrediFind. I am just working off memory here.
As far as the quick search - that might be a lot more difficult. See if there is a program there for that as well. Do you know what was installed on your computer before all of this happened?
Also go to Start - Programs - Start-Up - anything in there that was no in there before?
If the above does not help:
http://www.spychecker.com/program/hijackthis.html - download this & paste the results here.