> I already have a complete working setup built with Inno setup(it's 4.8
> mb), now I just need to get it as lite as posssible.

Tony, try Agentix Installer (http://www.aginstaller.com) to built the
litest setup for your IM server. It has very low (50Kb only) overhead.
It is very impressive indeed, doing almost everything Inno Setup does,
but producing setup files 250-290Kb smaller.