LiveCode 4.5 no longer requires a license key. Instead, it is activated by logging in with your user account details, and it checks your entitlement on the server. This is a more secure method of activation, and also prevents many issues with lost license keys and not being sure which one to enter. Here is how it is done. First ensure the computer you are licensing from is online. If you can't do this online, you need to use the manual activation file, I will post another lesson on this subject.

Go to
http://www.runrev.com/store/account/login/
and log in with your email address (1) and password (2). Click Login (3).

In your account, if you have an active license or a trial license, you will see download buttons below your license details. Click the appropriate button to download for your platform.

Install your downloaded LiveCode 4.5. When it has installed you will be presented with an activation screen. It will be on the "Automatic" tab by default, and unless you are offline or behind a firewall you should use this tab. Enter the same account details as you logged in to your account with and click Activate.

If you have more than one valid license in your account, it will prompt you to select your license. You can scroll across (1) to find the license you want to use, then click on Use License (2). That's it! Your LiveCode will now be licensed. You only have to do this once, the next time you start up LiveCode it will still be activated, and you do not need to be online to use it.