Highlight all the files Clients > use Ctrl + B to Backup to the flash drive

On the new computer > use Ctrl + R to Restore (Highlight all the files Clients from the flash drive) 

All of the steps are in this article https://accountants.intuit.com/support/en-us/help-article/download-products/install-lacerte-new-comp...

Edited to clarify what to copy from the program and not from the directories. Thank you @abctax55