I sent it to the support folks yesterday, once they closed my ticket and sent me their not so helpful resolution.
In detail, and keep in mind this works with Windows 7, probably with Vista, but I am not sure without testing, where it resides in XP, is what was needed.
The sync infomation resides in an XML file, and a series of files that end with .sync, the sync files have long, mixed character string names that are tied somehow to the AMT's I think.
The folder, containing those files, lives by default in:
I had that folder backed up in a standard backup on a separate drive.
After the new installation, I downloaded and synched my smallest tree, located that folder, and renamed it to preserve it. I thin copied the FamilyTreeMaker folder from the existing backup to replace the one I just renamed.
Launch Family Tree Maker, find and open the .ftm file and it should be linked as before.
This whole thing hinges on having backups, or, if moving to a new computer, making sure to copy those files from the old one.