If your desktop computer isn't recognizing peripherals, the first step is to turn off your computer and turn it back on. Unplug the power from the tower and, while it is disconnected, press and hold the power button for 2-3 seconds. Then release the power button, plug the power back in and try to turn it back on. If your computer boots up properly, it means that one of the peripherals you removed is causing the problem.To identify which device is causing the issue, you should reinstall each device on your computer and test them each time.
Once you've identified the specific device that's causing the problem, you can replace it or check with the device manufacturer for help.