Just make sure the actual clips are fine: play them in Windows Media player or
VLC
The FS100 outputs video as mpeg2
Windows Movie maker does not edit mpegs
Sony Vegas 9 certainly does, but it may be that the trial version will not allow you to edit mpeg files
I dont rate image mixer myself though Im unsure of why it isnt working
You could try downloading UleadVS ( or Corel) as they may allow it
In short
You dont have the right software (WMM is not it) and Image mixer is lacklustre
I suspect the full version of any of currently available software will do just fine
Ulead VS may actually allow this in trial but with reference to your ( other) thread on free good video editing software.. it doesnt exist
What might be "near free" are more recent versions of current software which may now be very affordable as the newest version are released
If you have the full Nero ( ver 6-9) on your system, Neros edting software Nero Vision will see your files and edit them even if it lacks the finnise of other more capable software