There are various methods to fix the issue of the mouse cursor disappears such as:
Update the Driver
Disable assistant
Disconnect Other External Devices
Uninstall New Programs
Scan the System
Check Battery Settings
Steps to Run Window Update Troubleshooter to fix Windows update error 0x80070643
Click the Start button, and go to Settings >> System >> Troubleshoot
Click Other troubleshooters.
From the list, find Windows Update and click “Run.”
