Until now, I had a very good solution for protecting Windows workstations. It was the only one guarantied by me. I'm not talking about professional and expensive tools. Out of question. I'm talking about free tools, accessible to all of us.
On short, after a fresh Windows install and swapping Internet Explorer with Firefox (and NoScript as add-on), next installing Comodo firewall and Avira antivirus. I never had any problems on systems tuned this way by me for friends and for my use.
Few days ago, I received from Avira an announce that I can use their product for free, another 10 months. After that, I must buy the product. This means that I will never install Windows systems for my friends but, if they want Linux I am available.
I know now are hard financial times for anybody and we all must survive but thanks God, we have Linux (and Wine for Windows addicted people).