internet security scan

hello all,

 

sorry if this is a silly question but when I run a full system scan with internet security 2008, underneath where it says 'scanning commonly affected files...' it goes through a list of files with names like w31.stration.d@mm, w32.sality.u, trojanhorse, adware.conspy, spybouncer and so on but it just ignores them as risks and continues scanning. firstly, are these files on my computer and if so why do i not get the option to remove them?.. secondly, if they are there how do i get rid of them?..