My Logitech K400+ keyboard stopped working after I upgraded my PC to Windows 11 a few years ago. The computer detects the Unifying receiver as "Unknown USB Device (Descriptor Request Failed)," and none of Logitech's software can see it. I replaced the batteries and inspected the keyboard, but everything appears normal. Today, the keyboard unexpectedly worked for about five minutes before the receiver stopped responding again. The same problem has occurred on five different computers. Could a driver update have damaged or disabled the receiver, or is the dongle simply failing?
1 Answer
The receiver itself is probably failing rather than the keyboard. Testing it on another computer is a good way to confirm, but since the same error appears on several systems, the USB dongle is the common point of failure. Working briefly before disappearing could happen if it was detected until Windows installed or changed a driver, but it may also indicate an intermittent hardware fault. If the keyboard is still within the seller’s or manufacturer’s warranty period, it’s worth contacting support even without the original receipt; proof of purchase may sometimes be recoverable through the retailer or payment record.
That would also explain why the Logitech software cannot detect it. If Windows reports a descriptor-request failure before the software even starts, the receiver is not properly identifying itself over USB. Try a different USB port, preferably a USB 2.0 port directly on the computer, but if the error remains across multiple PCs, replacing the receiver or the whole keyboard is likely the practical solution.