That's Lowrance topo, right?
I think that v6.3, requires (after installation on the computer) that the original, Lowrance CD is in the drive you loaded the program from. Also, in order to load maps on the card, a Lowrance card reader has to be registered with the software and connected and a card registered with the software has to be in the reader. Generic cards (not Lowrance) do work but the reader has to be a Lowrance one.
If all of the above is OK, the only other thought I have is; try updating ActiveX - should be able to find updates on Microsoft website. Other than that; you'll have to call Lowrance support.
HTH
Andrew Kalinowski