Will upgrading keep previous settings, connection information, and license key?
(For Toad for Oracle 10.1 or below)
Toad will keep all the previous settings, connection information and license key; as long as the installation of the new version is installed over the previous version. When installing, make sure the installation path is in the same directory where the current version is installed in. Otherwise Toad will be installed in it's own directory path with default settings and the previous installation of Toad will remain as normal, thus having both versions side-by-side.
(For Toad for Oracle 10.5 and above)
By default Toad will install in its own directory path, however when first launching Toad a user prompt will appear asking the user to either migrate settings from a previous version of Toad detected or it will prompt not to migrate any settings and perform a clean install. Choosing to migrate will automatically move over previous settings, connection information and license key; not migrating settings will put all settings at default, but should still migrate the license key, nevertheless.
(For Toad for Oracle 11.0 and above)
By default, Toad will automatically migrate settings from a previous version as long as it is no more than 3 versions behind. If a clean set of settings files is required, or you would like to migrate from a specific version of Toad, then use Utilities | Copy User Settings.