All of the data in your Generations 5.2 file is contained in the single file with the .uds file extension.If your Windows Explorer has the options set to not display the file extensions for known file types, it will be listed as a "Tree5" file.
Just copy that over to your new computer.Depending on how you plan to transfer it, you may wish to use a compression utility such as WinZip to produce a smaller file for the transfer (compress on old computer, move compressed file, uncompress on new computer).
You should take a look at the Generations Tip on installing and running the sofware on XP (http://users.sisna.com/mhobart).
Are you aware that Sierra has had a free patch to upgrade from v5.2 to v6.0.1 ?That has been available for many years.You can find it at ftp.sierra.com in the pub/patches/pc directory, the gen52to6010.exe file.
You may wish to take a look at my Generations Information Sources posting at my website (see above) and also the Generations Tip on program interactions.