FM license agreement allows you to install FM on more than one computer. You can only use one copy at a time. Just install FM on the new computer then it will ask for the license key when you install. If it is an upgrade version then the install will ask for current license key and the license key from previous upgradable version. If FM is not need on the old computer then just uninstall.
If you purchased a digital copy of FM and did not save a backup copy, then you will have to call FMI tech support to have them to resend you the email with the download link. Always make backups and I suggest downloading all version, which is Mac Version, Windows 32bit, and Windows 64bit. I store backups on dropbox.
If you are needing to use multiple copies of FM at the same time then you will need to purchase additional licenses.
Retrieving data ...