I have Windows XP Home Edition with Microsoft Wireless Multi Media Keyboard 1.1 - XP registers the keyboard as a laptop so the numeric keypad will not work.  How do I change XP to recognise the keyboard as using it's entire keyboard?  I'm sounding a bit desperate because I am.    
I also have Windows 2003 Office installed.

What is shown under keyboards in device manager?
Try updating the driver for whatever device is shown as the keyboard to the driver for the wireless keyboard you have. The latest Microsoft wireless keyboard driver [Intelletype Pro 6.1] is shown on their web site.
This may solve the problem.

Thank you for your reply.  I have done what you have suggested but I think I might have a problem with the motherboard not recognising the wireless keyboard properly.  Lucky it's in guarantee - my only problem is I'm an accountant and I am calculating without the numerical keyboard at G.S.T. time. Thank you for your time in answering my question.

Try updating the motherboard chipset drivers. These are what control the basic functions of all your hardware. You can obtain these at the web site for the chipset manufacturer [the two largest are Intel and Via].
The motherboard or computer manufacturers also usually either post these or give you links to them.
Good luck :)