I work with computer all day long son.
A corrupt file can be caused by a program not installing properly or running several program in the back-ground while installing a particular software at the time.
Just browing the net? I browse daily, yet I haven't had a virus in years, sure spyware does remove "cookies" but anyone can do that manually, no need to install a program that can do that, then again, ZoneAlarmPro gets rid of the spyware and it does it automatically.
Opening ANY e-mails is a major source of getting infected with a Virus, file sharing programs like Kaaza, media monkey, limewire are the major source of viruses and spyware, guess what? I don't use any of that crap and ZERO viruses for me.
Yes, the 7.1 versio, which is FREE is the one being discontinued which is what the thread is stating and the one that everyone here pretty much uses, the 7.5v is the one where you have to buy, no one wants to pay........now what part of that you didn't understand?