Check your computer is set up for the correct type of keyboard.
If the "3" numeric key (above the "W" and "E" keys) has a £ symbol, it is a UK keyboard. If not, it is probably a US keyboard.
Assuming you have Windows XP:
Go to Control Panel
Open "Regional and Language Options"
Select the "languages" tab
under "Text Services and input Languages" Click on "Details" button
Check which keyboard is set up and change if necessary, to match your hardware.
See more here: http://support.microsoft.com/kb/258824
Arthur Smith, October 2011