My iPhone 12 Pro now creates a "power surge on USB port" (Windows Explorer msg)to my desk top when I connect the phone to the desktop

The fundamental problem is your PC does not meet current power delivery standards for smartphones, which is a minimum of 1 amp (5 watts). Some less expensive PCs only have 1 USB port internally, to which they add an internal unpowered powered hub. On the PC side, try disconnecting all power using USB devices, such as external drives. If you are using an external USB hub, don’t. On the phone side, charge the phone to at least 80% before connecting it; the phone uses much less power for charging above 80%.

Hello Lancer2424,

Thanks for that info and for choosing the Apple Support Communities. If we understand correctly, you are unable to charge your iPhone with your Windows computer, as you get an error message. To help with this, please follow the steps in this Apple resource, including testing with different Lightning cables, test in different USB ports on the computer, and that all devices are up to date:

If your iPhone or iPod touch won't charge

Cheers!

Great, glad it’s resolved. That’s a solution known to the ancients and passed down over the centuries: When in doubt, reboot.