This message will appear usually on Windows 8, Windows 7, Windows Vista and 2008 machines that have the User Account Control activated. The program will be registered, it will not however activate the Abacus service.
You will need to exit out of the Abacus program. Re-enter the program by right-clicking the icon and selecting “Run as Administrator”. Windows will verify if you want to run the program as the administrator, say YES or OK to continue. Click File, and then Register. Your firm name and customer ID should still be in the next window. If they are, click the Activate button. You should now get a message saying you have been successfully activated. If you do not get any other error message you can exit and then continue the installation on the other machines in the office.