Yeah I have that one, SpyBot, and AVG Free as well as the Microsoft stuff and they cannot find or catch everything, not even close. Some of the more aggressive malware trojans can hide in the registry and morph around. When that happens, you have to isolate the computer from the internet and dig it out file by file, which takes hours. If you are lucky it will not remain dormant for long. The only defense against aggressive malware is isolation, because they hitch rides on internet downloads mostly. The last one I got was hidden in a free FLAC reader that I downloaded. If you download something, make sure it is from a quality source. Hackers know people go for free software before they will pay and they exploit that fact. But malware can also get in through some pretty strange sources, anything you hook to your computer anywhere/anytime is a security risk. The Chinese got caught sending malware in through Walmart photo albums a couple of years ago.