Keyboard RT7D50

Hi,

 

Recently I bought a Optiplex GX280 Desktop with Windows XP Professional Operating System. The computer comes with a keyboard Dell RT7D50. It does'nt work very well because I can't use the arroba sing, number sign o percent sign, etc etc that works with Alt+Control keys.

 

Someone tell me how I fix the problem?

 

Thanks,

 

Grobanii