If you have purchased the dongle, or internet dongle, simply use them on your new computer as you did on the previous.
If you have purchased the countercode version, you will be required to obtain a new countercode. Note that there is a $25 administrative charge for the a countercode. Please contact sales to obtain a new countercode. Once you have purchased the new countercode, you can install it following the instructions here.
Please note, your FCS Express license specifically precludes you using the countercode version on more than one computer.