Make a backup of ST 1.25 from your machine
C:\Program Files\NCH Swift Sound\SoundTap (the entire folder)
to reinstall on the other machine.
If you dont have your original ID & key, contact support through the many forms we have on our website, preferably the sountap or registration one. we may be able to find them and regen them for you. Outside of this you need to pay for an upgrade