What programs are good for converting to AVI?!?

I am currently trying to look for a program that can convert my videos (Ipod Nano Videos I got from Camera) but I cant find any online, I dont wanna pay for them too, most of the programs I used had like a expiration date and only limited amount of conversion to the video's. I tried AVS, VIDEOzilla, they expired and it doesnt work. I need most of my videos for school! Please help! Can I get the link to it too so i can download it for free?! Its due thursday!