Silent installation issue

Is it possible in a silent installation to set a switch that will force close down of a running version of HyperSnap ?
This is the command we use today: HS6Setup.exe -s -runafter -autostart -allusers -nodeskico
When I run it it tell me that one instance of HyperSnap is running and ask me if it should try to close it. I would like to have a switch that forces a close of the open instance.
 
Please provide this additional data: 
Exact HyperSnap version in use (from Help/About menu): 6.90.04
Windows version in use: WIN XP