How can my Windows 10 connect to 'Personal Hotspot' of my iPhone automatically My Personal Hotspot (henceforth PH) remains on, with the same password (see underneath). 



After clicking the Wireless icon on my notification area/system tray, I see 'iPhone' on my WiFi list and connect successfully.



Suppose that my iPhone remains on, but I shut down/hibernate/sleep my laptop. After I turn on my laptop again, why does 'iPhone' never appear on my laptop's WiFi list automatically? I have waited 10, 30, 60 mins, and repeated this process 5 times.

Then  I enter Settings > PH, change nothing, and see no changes. 3 mins. later, iPhone appears on my laptop's WiFi list.
The problem is with the iOS Personal Hotspot feature. By design, the network is discoverable only when the Hotspot screen is open. This means that your PC can't find the network when waking up/rebooting. Unfortunately there seems to be no workaround, I was looking for the same thing for my old car stereo, and I ultimately ended up getting a dedicated personal hotspot for it.

The only workaround is to open the Personal Hotspot screen every time you restart/wake up the PC.