Northern Ireland is the smallest of the four countries of the United Kingdom in terms of both area and population, containing 2.9% of the total population and 5.7% of the total area of the United Kingdom.
If you are using a wireless mouse with a USB connector and a PS/2 keyboard, verify that the USB mouse is plugged in a USB port on the computer and that the purple keyboard PS/2 plug is connected to the purple PS/2 port on the computer.
These days, most USB RF wireless mice employ what we call a nano dongle, a tiny receiver that juts out only a fraction of an inch from the USB port. We suggest looking for one of these if you use the mouse with a laptop, since you can typically leave these receivers inserted into the port when you transport your laptop.