HTC Sync does not open automatically and does not recognize phone

[AC Question]

I believe I have an HTC One M8 and it is updated to Lollipop. I have a new Win 10 HP Laptop, Sync Manager will not recognize phone but win 10 does. I have deleted and reinstalled sync manager. I have repaired it with the firewall turned off. I have tried an older version. Sometimes it seems to be connection but never for long.
What can I do. I want to import and backup my windows contacts. Thanks .