Keyboard problem typing some wrong symbols

Hi

 Im hoping someone can help me with my keyboard problem.

 I have a Dell E520 desktop since jan 2007

 My computer crashed about a month ago and I reloaded Windows XP but since then I found I cannot get my Keyboard that is a usb connection to type some correct symbols when those keys are pressed and it is only a few. 

 I have checked the Keyboard and it is set to UK, and the symbols I seem to having problems with are,  when i want to type the @ symbol I have to type " and vice verse if I want the " symbol I have to type the @ symbol, if I want the £ sign i get the # sign, and still not worked out where the £ symbol is, and im even more confused now as they are working correctly while im typing in the forum here, but if I try using in word to tpye in or try to write a e-mail they are as I have put down above and there are a couple other ones wrong also.

When I check the  keyboard in control panel it says it is a HID Keyboard with standard keyboard and it has 2 drivers showing C:\windows\system32\drivers\kbdclass.sys or  C:\windows\system32\drivers\kbdhid.sys.

Neither seem to work correctly when typing in word or e-mail programmes.

But as i said they are typing correct in here, so im not sure if that is a clue for someone, but thats a 1st time those symbols have worked correctly in 4 weeks

Thanks and i hope someone can advise me what weird and wonderful things are going on with my keyboard

Kevin