Updated to Win10 v1607 (64bit Home) and Ghost 15 showed need to enter product code again. I just navigated to C:\Program Files(x86)\Norton Ghost\Agent\VproSvc.exe. Right clicked for Properties and opened Compatibility. Win 7 was checked and greyed out. I just hit run Compatibility Troubleshooter, said to accept current values, hit test, accepted what was already there. Applied and closed. Restarted PC and no more prompts for product code and now with a green check on tray icon. I ran a single file restore and it worked with no problem. I then restored an entire C disk image using the boot disk at startup and restored to a spare HD. Worked flawlessly. System booted right up into new Win10 with no errors.
Good luck and I hope you get the same results with as little effort as I had.