I don’t know but I have had three alerts on these trojans in the Windows directory lately. I don’t know how they got there but I have had a bad problem with a lot of advertising spam with one of my ISP email accounts, which I’m dealing with. I’ve installed Script Sentry as added protection. I would go with the Avast Pro but their price lists shows an amount for 1 year. Does this mean that it costs $40 per year for Avast Pro? Anyway, I use W98 so the boot scan function for Avast Pro won’t work so I use F-prot for DOS for that.