Unfortunately Movie Story is not available for download.  You will lose this (and other software) if you do a clean install.

1.  You could have UPGRADED to Windows 7 which would have preserved your drivers, data, software etc.

2.  You could buy a Sony Camera that comes with this software bundled.

3.  You could buy alternative software.

The problem is caused by licensing restrictions where Sony proprietary software is only licensed to be bundled with the Sony version of the Operating System.  If you make a clean install using a commercial version of Windows you will lose these programs in Europe and they cannot be recovered.