a couple weeks ago my elderly and hesitant father decided to burn some dvd's in the early morning and because I was barely concious and I could not help him in a milllisecond, he went to google and got some random free dvd burning software (he cannot recall the name). Along with it, I noticed that in my (x86) program files (I cant remember if it is x64 or x86) I had a folder that was named ''Free offers from freeze.com'' and inside it it had .ico files if I remember correctly. These icons also appeared on my fathers desktop. These icons are the classic internet virus icons. one was the old dolphin with the name: dolphin.ico (can't remember exactly the names). Another one was a rip off loooking pacman that said: Free games as the name. right now I have removed the .icos from the freeze.com folder and from his desktop, but how do I know there are no viruses or other malware that came and was not detected by my malwarebytes, microsoft security essentials software? (both found none at all) I have done anti virus scans in safemode as well and nothing has been found. How can I check if there IS something that is malicious, how can I check if my registery has been modified and how to detect these culprits?