Go to Start > Search. In the search box, type in "C:/program files"
Search for the file which contains all the files for that Anti Spyware, and delete it.
If that doesn't work, and it's absolutely necessary to get rid of it, delete everything on your computer and start over.
But if there are no spywares or viruses, then I don't think you really have to worry about this spyware on your computer.
[I know what you mean, by the way; that always happened when I ghosted (or simply put my computer back to a past date) my computer and started all over. These spywares ads go away in about a week.]
Avatar: In memory of ieatwyverns <3
Thank you, Vasco <3