Hope this advice is not too late, but you might want to check this branch of Sony's FTP area:
ftp://ftp.vaio-link.com/PUB/OS/You should see two subdirectories there, and one is called XPDOWNGRADE. Inside, you will find drivers for about six different model types, unfortunately, FS is not one of them.
I have an FZ180E that I was extremely disappointed with once I discovered that none of my existing software was compatible with Vista. I went through the whole frustration of searching for XP drivers on Sony's support website, and then I discovered their hidden secret.

I'm now running XP with no problems. Hope this helps. You might also try snooping around more on that FTP server, the PUB area is pretty big, maybe you might find exactly what you are looking for.
Regards,
Bill.