if you have icons of both pj64 versions on your desktop or something, right click the old version icon select properties and press the go to target/open file location button.
copy the save folder. repeat with the new version and paste instead of copying.
otherwise try the standard location c:\program files\project64 1.?
__________________
pc configuration:
cpu: AMD Athlon 64 X2 6000+ 3.0GHz, GPU: GeForce 8800GTS 640MB, MoBo: Asus M2N32-SLI Deluxe, RAM: Corsair 6GB, case: Cooler Master Centurion 534, HDs: Seagate 500GB + 750GB +external 1TB, Os: Archlinux & Windows 7. my website