Dell XPS 18 (1810, Early 2013) - Manual (Page 25)

Using the Keyboard and Mouse
If you purchased a wireless keyboard and mouse with your computer,
they will be already paired. To use the keyboard and mouse, make sure
both devices have batteries installed and are powered on.
Pairing the wireless keyboard and mouse
If the keyboard and mouse do not work automatically you may need to
add them manually:
1 Swipe from the right edge of the display to access Charms.
2 Touch Settings → Change PC Settings→ Devices→ Add a
device, to manually add a keyboard and mouse.
NOTE: If the keyboard or mouse pairing has been lost for some reason,
use these steps to pair them again.
NOTE: The wireless keyboard and mouse may ship with a USB dongle.
You do not need to install the dongle to use the wireless keyboard and
mouse on this computer.
Using Your Computer │ 25