Hanh Tran Duc:
Thank you for your post.
Activation was only for the FileMaker Pro 9 product line. All future releases do not use activation; so, there is no need to deactivate the software. Registering your license key with FileMaker is another way for FileMaker to assist you with locating your license key if lost. The existing installation can be removed by the normal uninstall process for the Mac by trashing the FileMaker Pro 12 folder. Make sure to backup your existing databases to somewhere besides the application folder first.
Per the EULA, each license is allowed to reside on two installations, one main and one backup. The caveat is that the two licenses should not be used simultaneously or to share between each other via FileMaker Network Sharing; otherwise, a license key conflict will occur.TSFalconFileMaker, Inc.