Dell wireless keyboard and mouse KM636 may experience repeating keys issue. This issue is noticed when the keyboard and mouse when there is electromagnectic inteference with other devices running on the same radio frequency.
Updating the firmware of the USB receiver dongle to the latest version helps resolve the issue. The firmware update works only on the USB dongle that ships with the Dell Wireless Keyboard and Mouse KM636 model. The firmware update will fail when used on the USB dongle of a different wireless keyboard and mouse.