Automatically Connecting to a iPhone Hotspot from Windows 10

You seem to be thinking of Apple's Continuity feature, where an Apple device will automatically join a iPhone's Hotspot when within Bluetooth distance and each device is using eh same Apple ID for iCloud.

Not a feature for iCloud for Windows.

For the most part I was never far enough from the computer to drop the network (how far apart are you?) and the HP was set to join trusted networks and the hotspot was the only one it knew. If it didn’t autoconnect it was usually due to the iPhone going to sleep and dropping WiFi. If the iPhone was left plugged in at the office and I took the HP it would find the hotspot when I returned.

Go to the Microsoft support site and check.

Connect via WiFi instead.

Then you should not be losing the signal moving to another room. That sounds like an issue with your computer.

Ok, in that case click on the Contact Support link on the top right of this page and start the service process for your iPhone.

I’ve used an HP laptop with an iPhone 7 Plus, iPhone X and iPhone XS Max and did not have the problem you describe.

my iphone totally no response,I can't turn it on

It would have to be something on your Windows computer to make the request for the connection, if you can’t find such a setting then it can’t be done. You would have to have your hotspot active to do so for a Windows machine.