Some versions of LINGO require the user to input a license key.  Also, if you upgrade your copy of LINGO, then you will need to enter a new password. The File|License command prompts you for a new license key.

When you run the File|License command, you will be presented with the dialog box:

Carefully enter the key into the edit field, including hyphens, making sure that each character is correct. Click the OK button and, assuming the password was entered correctly, LINGO will display the About LINGO dialog box listing the features in the upgraded license. Verify that these features correspond to the license you intended to install.