Thanks to all for the suggestions.
I tried four of the above, but the file I needed was not even seen by any of the applications. It was a very small text document, erased by a syncing program.
I liked the Recuva program and the MiniTools Power Data Recovery. The Pareto Logic programs seems like it should be effective, it took about 2 hours to scan the disk, while the others only took minutes. But it found nothing.
The Recuva program has the advantage of offering a portable flash drive based version, which can be useful if you only have one partition on your computer, since you do not want to write to the partition you will be searching on.