You can't usually 'soft' boot your machine with 
[Ctrl] [Alt] [Del] while A-10 is running. But, 
if you have a bad mission and don't want to save
the results of a mission there is a short period 
while the next part of the program is loading when
you can 'soft' boot. After a bad mission but, 
while the next section is loading, hold down 
[Ctrl] [Alt] [Del]. When you restart the game it 
will be as if your awful mission never happened.