Just because it has the extension .ssf doesn't mean it's a "Sounds System File" it just means that some program on your computer has associated the extension .ssf with it.
I know nothing about SkyScan but that file is most probably the actual firmware image so I assume you need a seperate application that will load it onto your hardware, at least that's the way it works with most other firmware upgrades for other hardware (eg. SW SynScan controller).
EDIT: Ahhh didn't see you were talking about SynScan software, you need the SynScan Firmware Loader.
It think this is it:
http://www.skywatcher.com/swtinc/cus...1=1&class2=101