An EP2 serial number looks like
012345-6789AB-CDEF01
where the characters (except for the hyphens) are all hexadecimal
digits. It comes on some paperwork that comes with the product, not on
the hardware key nor on the CD (in fact, do not install from the CD, the
CDs are usually out of date, you should instead download the latest
version that matches your license from the PST website). License (i.e.,
serial) numbers are not tied to hardware keys, you may use any hardware
key with any valid license number. But you do need a valid license
number to get E-Prime fully installed & working.
If you cannot scare up the license number from your department, then you
could try contacting PST Support and see if they can recover the license
number for you.
-- David McFarlane