KG-STV is a different kind of digital SSTV that runs fine on Win7. It actually works more like traditional analog SSTV in that it scans line by line, horizontally or vertically, or if you like, randomly.
Although it is not widely used, it is interesting and can be found here, along with an informative technical description:http://www.g0hwc.com/kg-stv-english.htmlhttp://www.g0hwc.com/kg-stv-english.html
I have a SSTV webcam site that monitors KG-STV mode and posts received images to:http://dxring.net/indexsstvo.htm http://dxring.net/indexsstvo.htm
Otherwise, it's really hard to beat MMSSTV for analog modes.