try mounting the bin file to a virtual drive then extract the information from the file, which could be your avi. bin files can also contain various data aswell...from games to movies, just FYI.
Bin files cannot be converted to avi. A bin file is a binary compilation. Mount the file or burn it to disc. Use Alchohol http://www.alcohol-soft.com/ Or to burn the bin file to disc use infra recorder http://infrarecorder.sourceforge.net/ Check what files are in the bin file. Then you can encode them to avi using Mediacoder. http://mediacoder.sourceforge.net/ Edge
See if fairuse wizard can open and convert it. Fairuse converts ISO's to AVI. BIN are similar to an ISO, maybe it can convert it directly without you mounting it. http://www.fairusewizard.com/lang_en/fairuse_wizard_dvd_divx_xvid_backup_tool_light_edition.html
