Windows Mobile hotspot can share an existing connection with another device. The PC still needs a working upstream internet connection; switching on a hotspot cannot create internet access when that source is offline.

First verify that the Windows PC itself can reach the services you need. Establish whether its connection is Ethernet, Wi-Fi or cellular and whether you are allowed to share it. Workplace, accommodation and other managed networks may have their own rules. A cellular source also uses the allowance of its data plan.

Select the source deliberately

Open Settings, Network & internet, Mobile hotspot. Under Share my internet connection from, select the intended source. Choose the supported sharing method under Share over; Microsoft's guide describes Wi-Fi and Bluetooth options.

Review the hotspot properties before enabling it. Use a recognisable network name and a password that is not reused for another account. Check the available band setting if a receiving device cannot see the network, while keeping hardware compatibility in mind. Do not publish the password or QR code to solve a simple connection question.

Turn on Mobile hotspot. On the other device, choose that network and connect with the password or supported QR workflow. Confirm you have selected your hotspot rather than a similarly named nearby network.

Test both sides of the connection

Check that the receiving device can reach the required service, not merely that its Wi-Fi icon is connected. If the Windows PC works but the receiver does not, record that difference. Inspect the selected upstream source and hotspot settings before resetting either machine.

Be aware that the sharing PC must remain available; shutting it down or losing its upstream connection interrupts the receiver. Plan power and data use for the actual session.

When sharing is finished, turn Mobile hotspot off and confirm that the receiving device has moved to its usual connection or disconnected. A temporary handoff should not leave an unexplained wireless network running after the task ends.

Reference: Microsoft Support.