Question: how to transfer itunes library from old pc to windows 10?
Answer: Download CopyTrans TuneSwift from the following page: ... 
Run the program on the old PC and click on the “Transfer” button.
Next, click on “PC (Windows)”.
Now click on “New computer”. ... 
Select to the location where you want the iTunes library backup to be saved by clicking on the “Browse” button and click “Start transfer”.