I don't know what this sentence means: "Right vbottom on mouse pad makes it disappear". Do you have an English translation? My "mouse pad" has no bearing on what happens with my computer and how it operates. It's just a piece of foam with a cloth top so how could the mouse pad have any effect on the pc?
You will need to check all the INI files and "run=" registry entries as well as the Start Menu to see what's calling up the Search box.
Don't you have anti-malware software installed? If you don't, you need to get some. It's pure computer neglect to not have such software installed and updated.