InstallAware

I've bundle of setups (as self-extracting executables).
I would like to start them one by one from batch script. All settings are passed via parameters.
The problem is how to keep them in one thread. As soon as installer is started it forks and the next one is started. Then all commands are executed parallel in separate threads. Because they grab many resources, some of them are blocked and some are terminated when they try to get access to MSI engine used at this moment by other installer.
Finally, some installations goes smoothly when some is terminated on quite stochastic way.

My question is:
how to prevent installer from forking from starting thread? Any hidden option?

regards
Jarek

You probably don't want to use a batch file, but a master InstallAware setup. You can wait for setups to return inside InstallAware. Batch files have limitations like this and it may be hard to get them to wait - at any rate, this is outside the scope of InstallAware...