Download the Talk Now! Fix for Vista here.

You may receive a prompt from your anti-virus software, asking you whether you wish to allow or deny the download to proceed. Click ‘Allow’ to continue the download.

Once you have downloaded the fix, you will need to “extract” it (right-click and select extract). When you have extracted the program, you will need to run it by double-clicking on it.

Once the program has run, it will automatically restart Talk Now, which should now work.