how to delete nengine.dll

HI! Since yesterday I am trying to deal with nengine. I just can't remove the dll file from my computer. I searched for some help in google and I found this http://www.xp-vista.com/spyware-removal/remove-nengine-dll-virus-removal-guide
It has lots of information, but the things they suggest are not working. I found the folder but when I try to delete the file nothing happens.
What should i do? If I download malwarebytes will it help?
Thank you