@ ECHO OFF 

For/r % % I in (*. Scel) do start/wait "" "% % I 
"

So written, but can not be installed at the same time, after the need to install a file, and then there was a time of 10 seconds to automatically determine the
And then you can install the next file,
Is to add a delay time, but how to add, do not understand,
Can only help you bosses