I've had the Switch program installed for ages and never had problems with trojans or anything else. I also run Avast along with Spyblocker, Bazooka, A2, Spybot S&D, Spywareblaster, Crapcleaner and Adaware, all regularly updated. I would have thought that they would find any problems between them if there was anything to find. Could you have picked the trojans up anywhere else??
aziz7733 windows media player can create MP3s, for another free one then perhaps Audiograbber click here its free and works well, you do need to download the LAME decoder to allow you to alter the file sizes but its freeware as well. Full instructions on the website.