Turbotax won't let me into my tax return.

When I click on Turbotax I get a window that says Turbotax has been installed and I need to activate it.  I tried to open my return by clicking on the return itself but still get the "need to activate" message.  When I put in my code I get the message "all available activations for that code have been used.  Error code 603.  Anyone have any ideas how I can access my tax return?