help! i plugged an extra keyboard that i had to make
typing easier into my laptop. HOWEVER, since then, whenever i wish to
type without the extra desktop keyboard that i have, i
must have my fingers on the "fn" key on my laptop
keyboard. what do i need to do to correct this error?

You could try a System Restore to a point prior to using the external keyboard:

start > All Programs > Accessories > System Tools > System Restore


If that doesn't work: what is the exact make and model of the laptop?