Resolved keys transposed: shift + @ gives " ...

Folks,

An easy one for the expertise here, I'm sure.

I rebuild my IBM T42 laptop recently and all works well except that some keys aren't giving me what I expect, specifically

key for 2 (shift for ") gives me 2 and (shifted) @
key for ' (shift for @) gives me ' and (shifted) "
key for # (shift for ~) gives me \ and |
(the key for \ (shift for |) gives me \ and |, too; and i haven't been able to find hash and tilde assigned to any other keys [I had to paste these symbols in from Excel])

I'm sure there's a trivial explanation for this ... and I'll be very grateful to hear it ...

TIA

 

sorted: thank you

The odds were spot on - thank you. I had also acquired a tick in the supplemental langugae support boxes, removal of which freed up some more space.

Thanks