Occasionally, you might want to change the host ID that a certificate-based license uses for one of the following reasons:
Does Xilinx allow or provide a way to change the HostID of a certificated-based license file?
The end-user or administrator can initiate a rehost (Modify License) operation from the Xilinx Product Licensing website.
To modify an existing certificated-based license key file, click on the Manage License tab, select the license key file in the master view, and then click the Modify License button in the detail view.
After clicking to agree to destroy all copies of this old key, you will be able to generate a new key for the new machine.
Note: If you are entitled to a site license for a feature, simply visit the Xilinx Product Licensing website and generate a new license with the HostID of the new computer.