windows 7 sercurity tool

my son has the virus security tool on his laptop i have followed the removal instruction on you tube and removed it as i thought but there was another one as well that just had the number 27654 but it was security tool i was told to rename it which i did to BN but i still cannot get rid of it the thing is if you open the file its empty but it is still there i no it makes no sense as there is no file but it is still on the laptop how can i get rid of it in laymens terms please as i not that pc savvy

 

thanks buts its not that easy followed online instruction last night and have got rid of it now
christine