To transfer saves between PCs:
1) Open the save location on the old machine. Copy the saves onto an external device. Take note of what file number they are under. Save 1 is the auto-save and can be ignored.
2) Launch the game on the new machine. Make a character and save the game in all the same save file numbers from the old machine. The character name, stats, items etc. from these saves do not matter, since you won't be keeping them anyway.
3) Open the save location on the new machine. Select and delete every save in there (Save 1 can be ignored again). Open your external device and copy the old saves over.
Assuming everything was done in order, next time you launch the game from the new machine, your old saves will be playable.