Hy,i notice that you use translator for the italian text because is not quite perfect. Since nationzoom is a browser hijacking -spyware you can use junkware removal tool ,that you can download from here :
http://www.bleepingcomputer.com/down...-removal-tool/
i already used in the passed ,is simply ,you activate just by clicking on the installer and will clean all the malware from your pc. After this scan your pc whith malwarebytes .
If you done then go to settings of your browser and search for manage search engine- setup your own , also look into the extension and clean the nationzoom - is enought to delete this feature.
Sometimes ,the virus -in this case malware act strange when you try to remove from the installed program - be carefull of what the windows pop-up what say when try to delete -all that you do is only to hide from installed program. I wait a feed if you have made to clean your browser. Greetings.