Windows USB Code 43 Error: Causes and Quick Fix

What Does Code 43 Error Mean

Windows displays this notification when a device driver detects a hardware failure or incompatibility, causing the system to disable the device. The message typically appears in Device Manager with the text: This device cannot start. (Code 43).

The error can affect any peripheral component: USB flash drives, external SSDs, mice, keyboards, webcams, or smartphones in debugging mode. In most cases, the issue can be resolved at the software level without replacing hardware.

Causes

• Driver conflict or corruption. The failure often occurs after an automatic Windows update or after installing third-party port management utilities.
• Aggressive power management policy. The system cuts power to the port to save energy but fails to restore it correctly.
• Residual charge buildup. Static electricity on the motherboard or in the power supply blocks USB bus initialization.
• Physical hardware failure. A damaged cable, a worn-out device controller, or oxidized port contacts.

Troubleshooting Steps

Method 1: Hardware Reset and Port Swap

Start with basic diagnostics to rule out a temporary power glitch or a conflict with a specific port.

1. Disconnect the problematic device from the computer.
2. Completely shut down the PC. If you have a desktop, unplug the power cord from the outlet. For laptops, disconnect the power adapter and, if the design allows, remove the battery for 30 seconds.
3. Press and hold the power button for 20–30 seconds. This will drain residual voltage from the capacitors.
4. Connect the device to a different USB port. For desktop systems, use the ports on the rear motherboard panel, as they are directly managed by the chipset and are more stable than front-panel ports.

Method 2: Reinstall the Driver via Device Manager

Windows caches drivers, which can sometimes become corrupted. Manually removing the driver forces the system to install a fresh copy.

1. Press Win + X and select Device Manager.
2. Expand the Universal Serial Bus controllers or Human Interface Devices category.
3. Locate the item with a yellow exclamation mark or the name Unknown USB Device.
4. Right-click it and select Uninstall device. Confirm the action.
5. Restart your computer. The system will automatically scan for hardware and install the default drivers.

💡 Tip: If your mouse or keyboard also stops working, use a touchscreen or connect PS/2 peripherals to complete these steps.

Method 3: Disable Power Management

The operating system may forcibly "sleep" ports, which can cause initialization failures upon waking.

1. Open Device Manager (Win + X).
2. Under Universal Serial Bus controllers, double-click each item containing USB Root Hub or Generic USB Hub.
3. Go to the Power Management tab.
4. Uncheck Allow the computer to turn off this device to save power.
5. Repeat this for all hubs in the list and restart the PC.

Method 4: Full USB Stack Reset

If the previous methods fail, you will need to force a complete rebuild of the USB software layer.

1. In Device Manager, right-click every item under the Universal Serial Bus controllers category.
2. Select Uninstall device for all entries, including Host Controller and Hub.
3. Without performing a manual restart, open the Start menu and select Restart.
4. Wait for Windows to boot. The system will detect all connected USB controllers from scratch and register them in the registry without the previous errors.

Prevention

• Regularly install chipset driver updates from the official website of your motherboard or laptop manufacturer.
• Avoid using cheap, unpowered USB hubs: they often fail to provide stable voltage.
• Always use the Safely Remove Hardware feature before disconnecting storage devices to prevent file system corruption.
• When working with sensitive peripherals, disable Fast Startup in Power Options → Choose what the power buttons do, as it can sometimes interfere with bus initialization during PC boot.