Theoretically, USB suffers from performance problems when many devices are connected to the computer simultaneously. For example, when a printer, scanner, and webcam simultaneously place data transfer demands on USB, those devices are forced to share the available bandwidth. This can lead to errors.

If replugging or the Virtual Terminal works then goto step 6. If it doesn't work you should use either the PS/2 keyboard or the second machine in the LAN to login to your machine of which the keyboard stopped working. If your second machine is Linux use the command ssh user@host, if it is Windows use putty. Yes. When you connect an external USB keyboard to a laptop, it acts as a second keyboard, and both keyboards could be used at the same time. What if my keyboard has two USB cables? To this day I cannot remember which one (green or purple) is mouse and which is keyboard. I wish those two ports were interchangeable (i.e. mouse vs keyboard autodetection) like USB.The original PS/2 connection for keyboards and mice was designed to use a specific physical connector, but that’s not really part of the protocol those devices use to communicate, just like how copper Ethernet specifies a particular connector, but that connector has nothing to do with what is actually sent over the wire. The PS/2 protocol is still widely used in keyboards in laptops over a different type of internal connection because it’s more energy efficient than USB for keyboard usage, and it’s trivial to get it working with a modern operating system (literally just have something present essentially the same command interface that the original PC/AT keyboard controller did, which is actually pretty easy). Keyboards are pretty universal and can work with any desktop, laptop, or portable computer (PC or Mac) with the required keyboard port. When you plug a keyboard into a computer, it should immediately start working. With some more advanced keyboards with special keys or features, those features may not work until the software is installed. If the software is not compatible with your computer or operating system, you can continue to use the basic keyboard functions without the special features. If nothing on the keyboard works, you'll need to troubleshoot the keyboard with one of the links mentioned below. Can I plug my PC keyboard into my Apple computer?

Newer computers no longer have PS/2 ports. If you have a PS/2 keyboard and a computer with no PS/2 ports, we suggest purchasing a USB keyboard or a PS/2 to USB converter. Do all computers have a PS/2 port? PollingIterations [REG_DWORD] - Specifies the maximum number of times Windows 2000 polls the hardware. If the number of trials specified in this entry is exceeded, Windows 2000 stops polling. No, it’s absolutely correct. The information there is not talking about the physical connection, but the protocol being used to communicate with the device.After the keyboard is connected, it should be automatically detected and installed. If the keyboard has any special features, you need to install the keyboard software and drivers. How to enable the keyboard Wait until your USB keyboard stops working. Try if switching to a Virtual Terminal still works by pressing Ctrl-Alt-F1, are you able to login and enter commands? Try to unplug your USB keyboard and replug it to see if it starts working again.