In order to connect to specific databases, it is necessary to launch Toad as a different OS user i.e. Shift-Right-Click on Toad shortcut | 'Run as different user'. However, when this is done and the credentials are entered for the other domain\user, the following error occurs:
"Logon failure: user account restriction. Possible reasons are blank passwords not allowed, logon hour restrictions, or a policy restriction has been enforced"