Are you confusing an "ampersand" (&) with the "at" (This stupid system will not allow an "at") sign?
If so, the keyboard is set to the US layout. If that is the case, then upper case 3 will give a "hash" (#) instead of a "pound" (ÂŁ) sign.
If that is the case, assuming a version of Widows (you don't say) you need to go into the Windows settings and reset the keyboard to UK.
T
January 2011