When a phone connects over USB, file access runs through MTP - the Media Transfer Protocol. If its driver fails, you get the most confusing state in Windows: the phone clearly charges, may even appear in Explorer, but opens empty or throws "MTP USB Device - driver error". The fix is almost always on the Windows side, and it is quick.
Quick answer
Unlock the phone, pull down the notification shade, tap the USB notification and switch from "Charging only" to File transfer / MTP. No notification at all? Change the cable - charge-only cables have no data lines. If the mode is right and Explorer is still empty, reinstall the MTP entry in Device Manager - method 3 below.
Phones default to charging when connected. Until File transfer (MTP) is chosen on the phone, Windows has nothing to mount - this is the number one cause.
Many bundled and cheap cables carry power only. Without data lines, no USB mode selector even appears on the phone.
The Portable Devices entry in Device Manager failed or got mismatched - reinstalling it restores file access.
MTP relies on Windows Media components, which N editions ship without - installing Microsoft's free Media Feature Pack fixes MTP there.
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Download Driver Updater Downloads Outbyte Driver Updater for Windows 11, 10, 8 and 7. Free 2-day trial, no credit card required.Either the phone is locked (unlock it and keep the screen on), or it is still in charging mode - switch to File transfer in the USB notification. Both states make the phone visible but its storage inaccessible.
No. A USB stick mounts as a disk; MTP is a media protocol where the phone stays in control of its files. That is why a failed MTP driver leaves the phone visible-but-empty instead of missing entirely.
Yes - once MTP works, the Photos app import and Explorer both function. If import fails while Explorer works, unlock the phone and allow the access prompt it shows on first connection.