Ron,

In this kind of situation almost anything is possible, as Nick's post
would indicate. You can swap in a wired keyboard for the wireless one
(and turn off the wireless KB's driver software) for a definitive
answer.

There could be other software running on the "slow" computer that isn't
on the "normal" one. This could be a legitimate application or some
kind of virus or other malware (maybe a keystroke logger?).

You may need to turn off some processes one by one to see if one of
them is the culprit.