You cannot "move" a license over to another system just by copying the MEls.conf file.
The licenses in MEls.conf are generated for a "HW-ID" which is either a MAC-Adress of NIC
or it is the ID of MSU-Dongle.
Concerning Windows 8.1: You need release 18.1M030 or higher
See: http://de.ptc.com/WCMS/files/139811/en/System_Requirements_-_Creo_ElementsDirect_Drafting18_1.pdf
Since you went out of Support, you have no license and no right to run 18.1
Therefore, Windows 8 and Windows 8.1 are not supported by the Software you own.