Just copy over your .FTW file from Family Tree Maker 6 to your new computer - in Family Tree Maker 2012, select File>Open, and find that .FTW file. FTM 2012 will then create a new tree for you. Easy peasie.
FTM2012 can read .FTW files for FTM version 5 and up. Versions 1-4 (over 20 years old now) require separate conversion. If you have v5 through v16 BACKUP files (not original tree files with .FTW extension, but backup files with .FBC or .FBK extension) the files will require conversion to be readable in FMT2012.
FTM2012 can read .FTW files for FTM version 5 and up. Versions 1-4 (over 20 years old now) require separate conversion. If you have v5 through v16 BACKUP files (not original tree files with .FTW extension, but backup files with .FBC or .FBK extension) the files will require conversion to be readable in FMT2012.