If you receive a message that says An error occured while loading the license – license key is in use on another computer, this means you need to completely uninstall the Virtual TimeClock software on the old computer before you can license the software on your new computer. Virtual TimeClock licensing allows for one use of your license keys.
Virtual TimeClock Support Blog
Follow the moving guide for your edition of Virtual TimeClock to ensure you completely uninstall the software before registering on another computer.
Tip: If you are moving the TimeClock Server and you do not remove the background service when you uninstall the program, you have not fully uninstalled the program.