Plugging in a flash drive, mouse, or printer and receiving “Unknown USB Device (Device Descriptor Request Failed)” means Windows failed the initial USB enumeration handshake.
Why This Problem Happens
- Fast Startup caching a failed USB controller state.
- Dirty or loose physical USB port data pins.
Step-by-Step Troubleshooting Procedure
Step 1: Turn Off Fast Startup in Windows
Objective: Prevent caching of broken hardware state.
- Open Control Panel > Power Options > “Choose what the power buttons do”.
- Click “Change settings that are currently unavailable” and uncheck “Turn on fast startup”.
Step 2: Uninstall USB Root Hubs in Device Manager
Objective: Force Windows to re-enumerate hardware.
- Open Device Manager > Expand Universal Serial Bus controllers.
- Right-click each “USB Root Hub” and “Generic USB Hub” > Uninstall device, then restart your PC.
Step 3: Perform Cold Motherboard Power Drain
Objective: Discharge residual static electricity.
- Shut down PC completely, unplug power cable for 60 seconds, hold down the power button for 30 seconds, then reconnect power.
Verified Troubleshooting Tips
- Try plugging the device into a rear USB port directly attached to the motherboard to bypass front-panel cable interference.
Frequently Asked Questions
Could a bad cable cause Device Descriptor Request Failed?
Yes! If the data lines (D+ and D-) are broken inside the cable while power lines remain intact, enumeration will fail.