When using the Desktop/CD version of the program, the only place your .tax20nn file exists, is on the computer you prepared the return on, and any backups that you made. TurboTax does not have a copy in any format, of your tax file.
If anything, take the hard drive out of the old computer and install it in the new computer as a secondary hard drive. Then you'll find all your tax files on that secondary hard drive in the [drive letter]:\Users\[loginname]\Documents\TurboTax directory. just copy the contents of that folder to the documents\turbotax directory on your new computer.
