Just go ahead and install DIAdem on the new PC, using the CD you should have received with your DIAdem purchase. You can use the same license file on the new PC. Once DIAdem is installed, verify that it works properly and uninstall it from the old PC. You don't have to worry about DIAdem being installed on two PCs at the same time, as long as you only use it on one PC at a time ...
Otmar D. Foehner