I have had people contacting me saying there is a virus on my site but I've done countless scans and found nothing...It is all due to the fact that Norton and McAfee are utter garbage. So I was wondering, is there a way I could add something to detect if a user has one of those programs running and if so to display a message to them about it? I realize that this is a weird question and the answer very well and most likely is no but I just wanted to ask to make sure.
Short answer is no, you would have to have them install something like an ActiveX component before you can do something like that... if any site could scan a visitors PC for software it could easily attack vulnerabilities of them.