My roughly eight-year-old PC worked reliably until about a week ago. It first began powering on and then immediately shutting back down, so I suspected the power supply or a Windows 11 update. After reverting the update and disabling automatic updates, the PC started powering on normally, but every USB device disconnects just before or at the Windows login screen. The keyboard and mouse work during startup and in the firmware setup, but become unusable once Windows loads, so I can't reach Device Manager to inspect the USB controller drivers. I have already taken the computer apart and cleaned it thoroughly, but that did not help. The system is a prebuilt Asus GL10CS with an Intel Core i5-9400. How can I determine whether this is a Windows driver or software problem, a USB power-protection issue, or failing hardware?
3 Answers
The USB controller drivers may be damaged, but you don’t need a working mouse to troubleshoot immediately. Try reaching Windows Recovery by interrupting startup a few times, then use Safe Mode or System Restore. You could also connect through a different type of input device, such as a PS/2 keyboard if the motherboard supports it, to get into Windows and reinstall the chipset and USB drivers. Avoid assuming malware is the cause until an offline scan and an alternate operating system test point that way.
Try booting the computer from a Linux live USB made on another machine. If the keyboard and mouse continue working after Linux loads, the hardware and USB ports are probably fine and the problem is specific to Windows—possibly corrupted USB controller drivers, a bad update, or a policy setting. In that case, use Windows recovery options or create Windows installation media and consider repairing or reinstalling Windows.
Since the devices work before Windows starts, check the BIOS or UEFI setup first and confirm that USB support is enabled. You can also try different rear motherboard ports and disconnect every unnecessary USB device. If all ports shut down only when Windows loads, driver or operating-system corruption is more likely. If they also fail in a Linux live environment, the motherboard’s USB controller or its over-current protection may be shutting the ports off.
That makes sense. Since the keyboard and mouse work in the firmware setup, testing another operating system should help separate a Windows problem from a hardware fault.