I am a novice computer person and my Norton virus thingy says I have a Downloader Virus and I want to eliminate it. Please help me out and if you can be detailed.

Last night my PC registered a virus called the “Downloader” virus which Norton Internet Security/Anti-virus could not remove. It found the file which is called CLUSLXX.DLL but couldn’t do anything with it. I went to Norton’s website and they said to go in safe mode and run norton to remove it but this did not work. I can’t delete it or rename it because it says the file is in use.
What can I do to get rid of it? I don’t want to have to clear my PC if I don’t have to.
Thanks!

I ran a scan recently and it said i had the W32/Downloader virus. My anti-virus deleted it, then it came back. My anti-virus is freedom. I dont get any pop-ups (knock on wood) but if the reason im getting this virus because i download music from places like LimeWire and Kazza? I did download after I ran the first scan, so Im guessing thats what caused it, im not too good with computers so bear with me if this is a stupid question.
Thanks!