I've got Trend Micro Pc-cillin Internet Security 14, and a few months ago I accidently got smitfraud on my computer, but Trend couldn't do anything about it! As far as all the virus, spyware etc. scans were concerned, I was clean. Yet I had a changed home page and unwanted toolbar. What's up with that? I thought professional AV software was supposed to be good. Don't get me wrong, it's essential for stopping viruses from spreading once they infect your comp, but it doesn't work well in removing the infection.

So I was just wondering why this is. Feel free to give your opinions, thanks.

Smitfraud may be classified as sypware, therefore your AV might not detect it; if it cannot detect it, it cannot remove it.
Regards,
John

Possibly, except my Trend program has virus and spyware scans, and I naturally did both as well as a full scan. It was annoying that it couldn't do anything about it, even though its getting updates all the time. I'm thinking its because these programs weren't designed to go in depth scanning, that if you want to, you have to get special programs, such as from here.

And I just downloaded spybot and ad-aware se and ran scans on both of them, and they found things which my Trend program, that I pay for, can't even detect. Why is this?

There is as yet, no universally accepted criteria for what constitutes spy/adware; consequently, each company's application will look for---and find---a slightly different set. That is why one needs to use several anti-spyware applications: each will find things the others miss.
Cheers,
John

To elaborate on what jgweed has already stated. No single product is 100% foolproof and can detect and remove all threats at any given time. The security community is in a constant state of change as new malware infections appear. Each vendor has its own definition of what constitutes spyware and scanning your computer using different criteria will yield different results. The fact that each program has its own definition files means that some malware may be picked up by one that could be missed by another. Thus, a layered defense using several products to supplement your anti-virus and scanning in "safe mode" provides the most complete protection.

Ok, that makes sense. Thanks guys .