annoying error message!

My computer continually has error messages popping up and I know they are caused by adware. The error message says "cannot locate winupd.dll file not found". I scan with norton and it locates the file named  inetadpt.dll   everytime I try to delete the file the delete fails and the error messages continue to pop up. I followed Norton's directions to remove it, but I had no luck. The file is not in the registry. I located the file on my harddrive, but I am unable to remove it and it says access denied. Please help me fix this problem and stop the error messages.  Thanks

LRS