Thanks!.
Yes I have done as you said. That is, my application is getting added in Add/Remove program. I have "Detect Previous version" function implemented in my child installer for its GUID. and It detects properly If it is already installed.
Now I want to implement the samething in my parent installer where I need to detect the child application whether it is already installed or not?.

In that, can I detect GUID of child application from parent installer?

Regards
A Vijayasaravanan