nsExec is performing very slow

[123mobile]

I am using lot of already created exe files in my installer. I am prefering nsExec over exec as it allows me to redirect my output to the logfile. The problem is nsExec takes a long time to run and sometimes it is even not able to recover from minor errors, for which I have no Idea.
I would be very thankful if someone can shed light on this topic.

Thanks in advance,
Prabhat Jain.