When you do a search for "setup", it finds all of the files and folders on your comptuer that have the word, "setup", in their title. I am sure that there are many valid files and folders that have the word, "setup", in them. Removing them would mess things up.
There may be some files and folders that have the word, "setup", in them that are just temporary setup files, but you should verify that first before removing them. If you do not know whether they are valid or temporary, do not delete them.
We have a program that removes those type of files. It is called A1Click Ultra PC Cleaner. More information is located at http://regvac.com/fa1clean.htm