From the
http://www.pixinsight.com/faq/index.html page starting at 2.7
2.7 If I have to replace or format my hard disk, do I have to re-activate my license?
The PixInsight core application only asks for an online license activation if it can't find a valid license file. Your license file uniquely identifies you (the license holder) as a commercial PixInsight user. It is a very small file with the following name:
On OS X and Windows:
pixinsight-license
On FreeBSD and Linux:
.pixinsight-license
and is located on your home directory (or home folder):
On Linux and FreeBSD:
/home/<user-name> or /usr/home/<user-name>
On OS X:
/Users/<user-name>
On Windows Vista, Windows 7 and Windows 8:
C:\Users\<user-name>
where <user-name> is your actual user name on your operating system. If you simply copy your license file to the home directory of another machine you own, the commercial PixInsight application will run on that machine without problems. If you take the precaution to make a backup copy of your license file, then you'll never have to re-activate your license.
Alternatively, you can reactivate your license using our software distribution system. See FAQ 2.10 for details.
2.10 How can I reactivate my license?
To use PixInsight on a machine where you don't have a valid license file—for example, because you have lost your license, or after a computer crash—you need to reactivate your license. You can also use a license reactivation to move a trial license to a different machine.
Follow these steps to reactivate your license:
Visit our software distribution system and log in with your user name and password.
On the software distribution main page, click the License Reactivation link.
Read the information given and click the Request License Reactivation link.
Our system will send you an email with a verification link. The email will be sent to the address that you have associated with your license. Read the email and click the verification link if you want to reactivate your license. If you change your mind, just do nothing: the verification link will expire automatically after one hour.
You will receive a second email with new license activation codes for your license.
Mike
