This probably means you have a British keyboard but the computer thinks
it's American, Canadian or Australian - or vice versa, or something
along these lines.
If you're using Windows XP, go to the Control Panel,Regional and
Language Options, and click the Details button on the Languages tab.
This takes you to a dialog where you can change these settings. For
other versions of Windows, or if you need more help, find an appropriate
newsgroup to ask in: this one is for questions about database design
involving Microsoft Access.