As others have correctly noted, this will be your "locale" settings.
You don't mention whether the computer is running Windows, MacOS or one of the several flavours of Linux, so Windows is assumed.
If you hold down the Shift key and type the keys from 1 to 0 under the function keys, what do you get? Once you have configured the machine for UK settings, you should see this:
!"£$%^&*()
Just as a long shot, though, you have actually bought a computer with a UK keyboard, haven't you? I.e. the first line of letters should be:
QERTYUIOP