no. no antivirus. you have to completely trust all pieces of software you are installing. what exactly do you need to trade with Ib? operating system(original,not downloaded from P2P), java, TWS(preferably stand alone) and browser.clean install,cascaded network connection. and leave it alone. no flash,no browsing. maybe install firefox. IE is a piece of s** anyway. after that i would also disable few things in windows. such as firewall,automatic update,security center. seriously. to keep it clean and simple as possible. off course secure login in IB must be enabled with token or card.