Unless you changed the file location (I do for backup purposes) go to Local Disk (C):, ProWin25, 25Data.

Just transfering the data files to new computer will not do what you want. you have to make a back up, and then download PS to new computer, then use restore to get your clients on new computer

In 40 years never had to do a Backup Restore. Pre-today's technology I always moved files from one computer to the next (work to home and back) via 5 1/4 floppy, 3 1/2 floppy, USB, etc. Only issue was needed to do a Home Base Maintenance update, but now it'll tell you of a mismatch.